:root {
      --navy:        #0B1E3D;
      --navy-mid:    #122848;
      --navy-deep:   #060E1E;
      --gold:        #D4A745;
      --gold-light:  #FDE89C;
      --gold-pale:   #FFF4D0;
      --gold-grad:   linear-gradient(135deg, #7A4706 0%, #BA801E 15%, #F7CE55 35%, #FFF6DB 50%, #F5C642 65%, #AE7414 85%, #6A3802 100%);
      --gold-grad-text: linear-gradient(135deg, #965B0A 0%, #DE9F22 22%, #FFEAA0 46%, #FFFFFF 52%, #F9CE4D 68%, #B27513 88%, #6B3A03 100%);
      --white:       #FFFFFF;
      --off-white:   #F8F5EF;
      --text-dark:   #1A1A2E;
      --text-muted:  #6B7280;
      --font-serif:  'Playfair Display', Georgia, serif;
      --font-sans:   'Inter', system-ui, sans-serif;
      --radius-sm:   8px;
      --radius-md:   14px;
      --radius-lg:   20px;
      --radius-xl:   36px;
      --shadow-card: 0 6px 30px rgba(11,30,61,.1);
      --shadow-hover:0 16px 48px rgba(11,30,61,.2);
      --t:           all .35s cubic-bezier(.4,0,.2,1);

      /* ── TỈ LỆ 8 CỘT CHUẨN BOOTSTRAP (8/12 = 66.7% MÀN HÌNH, MAX 1080PX) ── */
      --container-max: 1080px;
    }

    *, *::before, *::after { margin: 0; padding: 0; box-sizing: border-box; }
    html {
      scroll-behavior: smooth;
      overflow-x: hidden;
      max-width: 100vw;
      width: 100%;
    }
    body {
      font-family: var(--font-sans);
      background: var(--off-white);
      color: var(--text-dark);
      overflow-x: hidden;
      max-width: 100vw;
      width: 100%;
      position: relative;
    }
    img { display: block; width: 100%; object-fit: cover; }
    a { text-decoration: none; color: inherit; }
    ::-webkit-scrollbar { width: 6px; }
    ::-webkit-scrollbar-track { background: var(--navy); }
    ::-webkit-scrollbar-thumb { background: var(--gold-grad); border-radius: 3px; }

    /* ── NAV (Canh theo 8 cột 1080px) ── */
    #nav {
      position: fixed; top: 0; left: 0; right: 0; z-index: 1000;
      height: 76px; display: flex; align-items: center; justify-content: center;
      background: rgba(11,30,61,0); backdrop-filter: blur(0);
      border-bottom: 1px solid transparent; transition: var(--t);
    }
    #nav.scrolled {
      background: rgba(11,30,61,.96); backdrop-filter: blur(20px); border-bottom-color: rgba(201,168,76,.25);
      box-shadow: 0 4px 24px rgba(0,0,0,.35);
    }
    .nav-inner {
      width: 88%; max-width: var(--container-max); margin: 0 auto;
      display: flex; align-items: center; justify-content: space-between;
    }
    .nav-logo { display: flex; align-items: center; gap: 12px; text-decoration: none; }
    /* Logo nhỏ góc trái: Mịn màng, chống răng cưa, tăng size rõ nét */
    .nav-logo img {
      height: 64px;
      width: auto;
      max-width: 175px;
      object-fit: contain;
      image-rendering: auto;
      filter: drop-shadow(0 2px 10px rgba(0,0,0,.6));
      transition: var(--t);
    }
    .nav-logo:hover img { transform: scale(1.04); }
    .nav-links { display: flex; list-style: none; gap: 2px; }
    .nav-links a {
      color: rgba(255,255,255,.85); font-size: .78rem; font-weight: 500;
      padding: 7px 11px; border-radius: 18px; transition: var(--t);
    }
    .nav-links a:hover { color: #FFD700; background: rgba(201,168,76,.15); }
    .nav-links a.active { color: var(--navy); background: var(--gold-grad); font-weight: 700; }

    /* Nút bấm Menu thu nhỏ (1 nút nhỏ gọn, tinh tế) */
    .nav-toggle {
      display: none;
      flex-direction: column;
      align-items: center;
      justify-content: center;
      gap: 5px;
      cursor: pointer;
      width: 44px;
      height: 44px;
      padding: 8px;
      background: rgba(11,30,61,0.85);
      border: 1.5px solid rgba(201,168,76,0.5);
      border-radius: 12px;
      box-shadow: 0 4px 16px rgba(0,0,0,0.45);
      backdrop-filter: blur(10px);
      -webkit-backdrop-filter: blur(10px);
      transition: var(--t);
    }
    .nav-toggle:hover, .nav-toggle:focus-visible {
      background: rgba(18,40,72,0.98);
      border-color: var(--gold);
      transform: scale(1.06);
    }
    .nav-toggle span {
      display: block; width: 22px; height: 2px; background: var(--gold-light);
      border-radius: 2px; transition: var(--t);
    }
    .nav-toggle.open span:nth-child(1) { transform: translateY(7px) rotate(45deg); background: #FFD700; }
    .nav-toggle.open span:nth-child(2) { opacity: 0; transform: scaleX(0); }
    .nav-toggle.open span:nth-child(3) { transform: translateY(-7px) rotate(-45deg); background: #FFD700; }

    /* Menu Mobile Drawer */
    .nav-mobile {
      position: fixed; top: 76px; left: 0; right: 0; bottom: 0;
      background: rgba(6,14,30,0.98); backdrop-filter: blur(24px); -webkit-backdrop-filter: blur(24px);
      z-index: 999;
      display: flex; flex-direction: column; align-items: center; justify-content: flex-start;
      padding: 24px 20px 48px; gap: 10px;
      overflow-y: auto; -webkit-overflow-scrolling: touch;
      visibility: hidden;
      pointer-events: none;
      transform: translateX(100%);
      transition: transform .35s cubic-bezier(.4,0,.2,1), visibility .35s cubic-bezier(.4,0,.2,1);
      border-top: 1px solid rgba(201,168,76,0.25);
    }
    .nav-mobile.open {
      visibility: visible;
      pointer-events: auto;
      transform: translateX(0);
    }
    .nav-mobile a {
      color: var(--white); font-size: .95rem; font-weight: 600;
      padding: 12px 24px; width: 100%; max-width: min(320px, 100%); text-align: center;
      border: 1px solid rgba(201,168,76,.25); border-radius: var(--radius-xl);
      background: rgba(255,255,255,.05); transition: var(--t); text-decoration: none;
    }
    .nav-mobile a:hover, .nav-mobile a.active {
      background: var(--gold-grad); color: var(--navy); border-color: var(--gold); font-weight: 700;
      box-shadow: 0 4px 16px rgba(255,215,0,.35);
    }

    /* ── MOBILE NAV: HOÀN TOÀN KHÔNG DÙNG THANH BAR, LOGO VÀ MENU LUÔN NẰM TRỰC TIẾP TRÊN NỀN SUỐT TRANG ── */
    @media (max-width: 1024px) {
      #nav, #nav.scrolled {
        height: 86px !important;
        /* Hoàn toàn không dùng thanh bar ở bất kỳ vị trí cuộn nào: logo và nút bấm luôn nổi trên nền */
        background: transparent !important;
        backdrop-filter: none !important;
        -webkit-backdrop-filter: none !important;
        border: none !important;
        border-bottom: none !important;
        box-shadow: none !important;
        padding: 8px 4% !important;
        pointer-events: none !important; /* Vùng trong suốt không chắn click/chạm vào nội dung bên dưới */
      }
      .nav-inner {
        width: 100% !important;
        max-width: 100% !important;
        pointer-events: none !important;
      }
      /* Logo và Nút bấm Menu góc phải: Luôn nổi độc lập trên nền trang web, tương tác bình thường */
      .nav-logo, .nav-toggle {
        pointer-events: auto !important;
      }
      /* Ẩn hoàn toàn 10 liên kết chữ gây tràn màn hình mobile */
      .nav-links { display: none !important; }
      /* Nút bấm Menu thu nhỏ */
      .nav-toggle { display: flex !important; }
      /* Logo HUB: Luôn giữ kích thước lớn 74px, sắc nét trên mọi nền suốt chiều dài trang web */
      .nav-logo img, #nav.scrolled .nav-logo img {
        height: 74px !important;
        max-height: 80px !important;
        max-width: 200px !important;
        filter: drop-shadow(0 2px 8px rgba(0,0,0,0.55)) drop-shadow(0 4px 16px rgba(0,0,0,0.35)) !important;
      }
      /* Thanh tiến trình cuộn trang bám sát mép đỉnh trên cùng */
      #progress-bar { top: 0 !important; }
      /* Menu ngăn kéo khi mở phủ từ đỉnh màn hình */
      .nav-mobile {
        top: 0 !important;
        padding-top: 96px !important;
        border-top: none !important;
      }
    }

    /* ── PROGRESS BAR ── */
    #progress-bar { position: fixed; top: 70px; left: 0; height: 3px; background: var(--gold-grad); z-index: 1001; width: 0%; transition: width .1s linear; }

    /* ── 1. HERO (ScrollTrigger Pin & Scrub - Slide 2 & 3) ── */
    #hero {
      position: relative;
      height: 100vh;
      width: 100%;
      display: flex;
      align-items: center;
      justify-content: center;
      overflow: hidden;
      background: var(--navy);
    }
    #hero-bg { position: absolute; inset: 0; }
    #hero-bg img { width: 100%; height: 100%; object-fit: cover; opacity: .72; transform: scale(1.05); filter: blur(3px); }
    #hero-bg::after {
      content: ''; position: absolute; inset: 0;
      background: linear-gradient(to top, rgba(11,30,61,1) 0%, rgba(11,30,61,.75) 42%, rgba(11,30,61,.35) 100%);
    }
    #particles-canvas { position: absolute; inset: 0; z-index: 1; pointer-events: none; }
    .hero-content {
      position: relative; z-index: 2; text-align: center; padding: 0 20px;
      width: 88%; max-width: 820px; margin: 0 auto;
      display: flex; flex-direction: column; align-items: center; justify-content: center;
      will-change: transform, opacity;
    }
    .hero-logo-box {
      position: relative; width: 100%; display: flex; align-items: center; justify-content: center;
      margin-bottom: 20px; min-height: 220px;
    }
    /* Logo 50 năm: Vừa mở trang là LỚN (scale: 1.8), không tự thu nhỏ nếu đứng yên */
    .hero-logo-img {
      width: clamp(180px, 24vw, 280px);
      object-fit: contain;
      filter: drop-shadow(0 10px 30px rgba(255,215,0,.45));
      opacity: 1;
      transform: scale(1.8) translateY(20px);
      transform-origin: center center;
      will-change: transform, opacity;
    }
    /* Khối chữ: Ẩn ban đầu, chỉ hiện ra khi người dùng cuộn chuột */
    .hero-text-group {
      opacity: 0;
      transform: translateY(35px);
      will-change: transform, opacity;
    }
    .hero-title {
      font-family: var(--font-serif);
      font-size: clamp(1.6rem, 3.6vw, 2.7rem);
      font-weight: 800;
      color: var(--white);
      line-height: 1.25;
      margin-bottom: 16px;
      letter-spacing: .02em;
    }
    .hero-title .hl {
      background: var(--gold-grad-text);
      -webkit-background-clip: text;
      background-clip: text;
      -webkit-text-fill-color: transparent;
      filter: drop-shadow(0 0 8px rgba(255,215,0,.35));
    }
    .hero-sub {
      font-size: clamp(.86rem, 1.6vw, 1rem);
      color: rgba(255,255,255,.85);
      line-height: 1.75;
      max-width: 600px;
      margin: 0 auto 30px;
      font-weight: 300;
    }
    .hero-cta {
      display: inline-flex; align-items: center; gap: 9px;
      background: var(--gold-grad); color: var(--navy);
      font-weight: 700; font-size: .9rem; padding: 12px 30px;
      border-radius: var(--radius-xl); letter-spacing: .05em;
      transition: var(--t);
      box-shadow: 0 8px 30px rgba(255,215,0,.32);
    }
    .hero-cta:hover { transform: translateY(-2px) scale(1.03); box-shadow: 0 14px 40px rgba(255,215,0,.5); }
    .hero-cta svg { width: 17px; height: 17px; }
    .scroll-indicator {
      position: absolute; bottom: 28px; left: 50%; transform: translateX(-50%);
      z-index: 2; display: flex; flex-direction: column; align-items: center; gap: 7px;
      color: rgba(255,255,255,.55); font-size: .72rem; letter-spacing: .12em;
      transition: opacity .3s ease;
    }
    .scroll-line { width: 1px; height: 38px; background: linear-gradient(to bottom, #FFD700, transparent); animation: sp 2s ease-in-out infinite; }
    @keyframes sp { 0%,100% { opacity: .3; transform: scaleY(.5); transform-origin: top; } 50% { opacity: 1; transform: scaleY(1); } }

    /* ── TẤT CẢ SECTION: ĐỀU GỌN GÀNG TRONG KHUNG 8 CỘT (MAX-WIDTH: 1080px) ── */
    section, header, footer, main {
      position: relative;
      overflow-x: clip;
      max-width: 100vw;
    }
    @supports not (overflow-x: clip) {
      section, header, footer, main {
        overflow-x: hidden;
      }
    }
    .si {
      width: 88%;
      max-width: var(--container-max);
      margin: 0 auto;
      padding: 76px 0;
    }
    .slabel {
      font-size: .74rem; letter-spacing: .18em; text-transform: uppercase; margin-bottom: 8px;
      font-weight: 700; background: var(--gold-grad-text); -webkit-background-clip: text;
      background-clip: text; -webkit-text-fill-color: transparent; display: inline-block;
    }
    #message .slabel,
    #identity .slabel,
    #alumni .slabel,
    #events .slabel,
    #media .slabel,
    #memories .slabel {
      padding: 5px 16px;
      border-radius: 999px;
      border: 1px solid rgba(212, 167, 69, 0.45);
      background-image: var(--gold-grad-text), linear-gradient(var(--navy), var(--navy));
      -webkit-background-clip: text, border-box;
      background-clip: text, border-box;
      -webkit-text-fill-color: transparent;
      box-shadow: 0 2px 8px rgba(11, 30, 61, 0.16);
      margin-bottom: 12px;
    }
    .stitle { font-family: var(--font-serif); font-size: clamp(1.6rem, 3.2vw, 2.4rem); font-weight: 700; color: var(--navy); line-height: 1.25; margin-bottom: 14px; }
    .sdiv { width: 52px; height: 3px; background: var(--gold-grad); border-radius: 2px; margin-bottom: 22px; }
    .stext { font-size: .94rem; line-height: 1.8; color: var(--text-muted); max-width: 740px; }

    /* ── PROGRESSIVE SCROLL REVEAL (Hiệu ứng "dần xuất hiện" rõ ràng, mượt mà và sâu sắc hơn) ── */
    .reveal, .reveal-left, .reveal-right, .reveal-scale, .reveal-tile {
      opacity: 0;
      transition: opacity 0.95s ease-out, transform 1.05s cubic-bezier(0.16, 1, 0.3, 1);
      will-change: opacity, transform;
    }
    /* Tăng biên độ di chuyển từ 35px lên 55px để cảm nhận rõ chuyển động trượt lên thanh thoát */
    .reveal { transform: translateY(55px); }
    .reveal-left { transform: translateX(-65px); }
    .reveal-right { transform: translateX(65px); }
    .reveal-scale { transform: scale(0.88) translateY(30px); }
    .reveal-tile { transform: perspective(800px) rotateX(24deg) translateY(45px); }

    /* Khi vào vùng nhìn: Hiển thị mượt mà không ghi đè hiệu ứng hover */
    .in-view {
      opacity: 1 !important;
      transform: none;
    }

    /* Hiệu ứng trễ so-le (Staggered Delay) giúp các thẻ xuất hiện nối tiếp từng nhịp như làn sóng */
    .pku-tile.reveal-tile {
      transition-delay: calc(var(--tile-i, 1) * 80ms);
    }

    .gift-blocks .gblock:nth-child(1) { transition-delay: 0.1s; }
    .gift-blocks .gblock:nth-child(2) { transition-delay: 0.22s; }
    .gift-blocks .gblock:nth-child(3) { transition-delay: 0.34s; }

    .ev-list .ev-card:nth-child(1) { transition-delay: 0.1s; }
    .ev-list .ev-card:nth-child(2) { transition-delay: 0.22s; }
    .ev-list .ev-card:nth-child(3) { transition-delay: 0.34s; }

    .up-list .up-item:nth-child(1) { transition-delay: 0.12s; }
    .up-list .up-item:nth-child(2) { transition-delay: 0.24s; }
    .up-list .up-item:nth-child(3) { transition-delay: 0.36s; }
    .up-list .up-item:nth-child(4) { transition-delay: 0.48s; }

    .pub-grid .pub-card:nth-child(1) { transition-delay: 0.1s; }
    .pub-grid .pub-card:nth-child(2) { transition-delay: 0.22s; }
    .pub-grid .pub-card:nth-child(3) { transition-delay: 0.34s; }
    .pub-grid .pub-card:nth-child(4) { transition-delay: 0.46s; }

    .tl-item:nth-child(1) { transition-delay: 0.1s; }
    .tl-item:nth-child(2) { transition-delay: 0.22s; }
    .tl-item:nth-child(3) { transition-delay: 0.34s; }
    .tl-item:nth-child(4) { transition-delay: 0.46s; }
    .tl-item:nth-child(5) { transition-delay: 0.58s; }
    .sec-logo-wm { position: absolute; opacity: .05; pointer-events: none; z-index: 0; right: 2%; bottom: 4%; width: clamp(100px, 10vw, 160px); }
    .sec-logo-wm img { width: 100%; height: auto; object-fit: contain; }

    /* Điều chỉnh chuyển động và bố cục lề trên màn hình điện thoại di động */
    @media (max-width: 768px) {
      .si {
        width: 92%;
        padding: 54px 0;
      }
      /* Hiệu ứng xuất hiện trên Mobile: Tăng tốc, dứt khoát, nẩy nhẹ và chuyển động sắc nét */
      .reveal, .reveal-left, .reveal-right, .reveal-scale, .reveal-tile {
        transition: opacity 0.62s cubic-bezier(0.25, 1, 0.5, 1), transform 0.68s cubic-bezier(0.22, 1, 0.36, 1) !important;
        will-change: opacity, transform;
      }
      /* Biên độ trượt dọc 44px bằng translate3d tăng tốc phần cứng GPU riêng biệt */
      .reveal { transform: translate3d(0, 44px, 0) !important; }
      .reveal-left { transform: translate3d(0, 44px, 0) !important; }
      .reveal-right { transform: translate3d(0, 44px, 0) !important; }
      .reveal-scale { transform: translate3d(0, 26px, 0) scale(0.92) !important; }
      .reveal-tile { transform: translate3d(0, 36px, 0) !important; }

      /* Rút ngắn bước trễ so-le (staggered delay) trên mobile để đón đầu cử chỉ vuốt ngón tay */
      .pku-tile.reveal-tile { transition-delay: calc(var(--tile-i, 1) * 45ms) !important; }
      .gift-blocks .gblock:nth-child(1) { transition-delay: 0.05s !important; }
      .gift-blocks .gblock:nth-child(2) { transition-delay: 0.12s !important; }
      .gift-blocks .gblock:nth-child(3) { transition-delay: 0.19s !important; }
      .ev-list .ev-card:nth-child(1) { transition-delay: 0.05s !important; }
      .ev-list .ev-card:nth-child(2) { transition-delay: 0.12s !important; }
      .ev-list .ev-card:nth-child(3) { transition-delay: 0.19s !important; }
      .up-list .up-item:nth-child(1) { transition-delay: 0.06s !important; }
      .up-list .up-item:nth-child(2) { transition-delay: 0.12s !important; }
      .up-list .up-item:nth-child(3) { transition-delay: 0.18s !important; }
      .up-list .up-item:nth-child(4) { transition-delay: 0.24s !important; }
      .pub-grid .pub-card:nth-child(1) { transition-delay: 0.05s !important; }
      .pub-grid .pub-card:nth-child(2) { transition-delay: 0.12s !important; }
      .pub-grid .pub-card:nth-child(3) { transition-delay: 0.19s !important; }
      .pub-grid .pub-card:nth-child(4) { transition-delay: 0.26s !important; }
      .tl-item:nth-child(1) { transition-delay: 0.05s !important; }
      .tl-item:nth-child(2) { transition-delay: 0.12s !important; }
      .tl-item:nth-child(3) { transition-delay: 0.19s !important; }
      .tl-item:nth-child(4) { transition-delay: 0.26s !important; }
      .tl-item:nth-child(5) { transition-delay: 0.33s !important; }
    }

    /* ── 2. MESSAGE & PKU STATS GRID ── */
    #message { background: var(--white); }
    .msg-top-grid { display: grid; grid-template-columns: 1.2fr 1fr; gap: 36px; align-items: center; margin-bottom: 32px; }
    @media(max-width: 860px) { .msg-top-grid { grid-template-columns: 1fr; gap: 24px; text-align: center; } }
    .msg-quote {
      font-family: var(--font-serif); font-size: 1.25rem; font-weight: 600; color: var(--navy);
      line-height: 1.5; position: relative; padding-left: 20px;
    }
    .msg-quote::before { content: '"'; position: absolute; left: 0; top: -12px; font-size: 3.4rem; color: var(--gold); line-height: 1; font-family: var(--font-serif); }
    .logo50-visual { display: flex; align-items: center; justify-content: center; }
    .logo50-visual img { width: clamp(190px, 22vw, 280px); object-fit: contain; filter: drop-shadow(0 8px 24px rgba(255,215,0,.35)); }

    /* Nút Về chúng tôi (Slide 6 - SJTU Style) */
    .msg-about-btn {
      display: inline-flex;
      align-items: center;
      gap: 8px;
      color: var(--navy);
      font-weight: 700;
      font-size: 0.92rem;
      letter-spacing: 0.04em;
      padding: 9px 20px;
      border-radius: var(--radius-xl);
      border: 1.5px solid var(--gold);
      background: rgba(201, 168, 76, 0.1);
      transition: var(--t);
      margin-top: 18px;
    }
    .msg-about-btn span { font-size: 1.1rem; transition: transform 0.25s ease; }
    .msg-about-btn:hover {
      background: var(--gold-grad);
      color: var(--navy);
      transform: translateX(4px);
      box-shadow: 0 6px 20px rgba(201, 168, 76, 0.35);
    }
    .msg-about-btn:hover span { transform: translateX(4px); }

    /* PKU Stats Mosaic Grid (Slide 7 & 8 - Peking University Style) */
    .pku-stats-container {
      position: relative;
      border-radius: var(--radius-lg);
      overflow: hidden;
      padding: 32px 24px;
      margin-top: 24px;
      background: linear-gradient(135deg, rgba(11,30,61,0.92) 0%, rgba(18,40,72,0.85) 100%), url('/anniversary/images/hub50_memories_campus_1786009270131.jpg') center/cover no-repeat;
      border: 1px solid rgba(201,168,76,0.35);
      box-shadow: 0 14px 40px rgba(11,30,61,0.22);
    }
    .pku-grid-header {
      display: flex; align-items: center; justify-content: space-between; margin-bottom: 20px; flex-wrap: wrap; gap: 10px;
      border-bottom: 1px solid rgba(201,168,76,0.22); padding-bottom: 14px;
    }
    .pku-grid-header h3 { font-family: var(--font-serif); font-size: 1.15rem; color: var(--white); font-weight: 700; }
    .pku-grid-header span { color: var(--gold-light); font-size: .8rem; letter-spacing: .08em; text-transform: uppercase; font-weight: 600; }

    /* Lưới mosaic số liệu: 12 cột cho phép bố cục cân đối Hàng 1 (3 ô span 4), Hàng 2 (4 ô span 3), Hàng 3 (3 ô span 4) */
    .pku-mosaic-grid {
      display: grid;
      grid-template-columns: repeat(12, 1fr);
      gap: 14px;
    }
    .pku-tile.span-4 {
      grid-column: span 4;
    }
    .pku-tile.span-3 {
      grid-column: span 3;
    }
    @media(max-width: 900px) {
      .pku-mosaic-grid {
        grid-template-columns: repeat(2, 1fr);
        gap: 12px;
      }
      .pku-tile.span-4,
      .pku-tile.span-3 {
        grid-column: span 1;
      }
    }
    @media(max-width: 520px) {
      .pku-mosaic-grid {
        grid-template-columns: 1fr;
        gap: 10px;
      }
      .pku-tile.span-4,
      .pku-tile.span-3 {
        grid-column: span 1;
      }
    }

    .pku-tile {
      border-radius: var(--radius-sm);
      overflow: hidden;
      min-height: 135px;
      display: flex;
      flex-direction: column;
      justify-content: center;
      transition: all 0.35s cubic-bezier(.4,0,.2,1);
      position: relative;
    }
    /* Ô số liệu nền xanh navy đậm */
    .pku-tile.solid {
      background: rgba(11, 30, 61, 0.92);
      border: 1px solid rgba(201, 168, 76, 0.28);
      padding: 18px 14px;
      text-align: center;
      backdrop-filter: blur(6px);
      box-shadow: 0 4px 18px rgba(0,0,0,0.2);
    }
    .pku-tile.solid:hover {
      transform: translateY(-4px) scale(1.02);
      border-color: rgba(255, 215, 0, 0.7);
      background: rgba(18, 40, 72, 0.98);
      box-shadow: 0 10px 30px rgba(0,0,0,0.35);
    }
    /* Ô cửa sổ trong suốt lộ ảnh HUB bên dưới: Căn giữa đồng bộ như các ô số liệu */
    .pku-tile.photo-window {
      background: rgba(11, 30, 61, 0.32);
      border: 1px dashed rgba(201, 168, 76, 0.45);
      padding: 18px 14px;
      display: flex;
      flex-direction: column;
      justify-content: center;
      align-items: center;
      text-align: center;
      position: relative;
      overflow: hidden;
      backdrop-filter: blur(2px);
    }
    .pku-tile.photo-window::before {
      content: '';
      position: absolute;
      inset: 0;
      background: radial-gradient(circle at center, rgba(11,30,61,0.65) 0%, rgba(6,14,30,0.85) 100%);
      transition: var(--t);
    }
    .pku-tile.photo-window:hover::before {
      background: radial-gradient(circle at center, rgba(11,30,61,0.45) 0%, rgba(6,14,30,0.75) 100%);
    }
    .pku-tile.photo-window:hover {
      transform: translateY(-4px) scale(1.02);
      border-color: rgba(255, 215, 0, 0.7);
      border-style: solid;
      box-shadow: 0 10px 30px rgba(0,0,0,0.35);
    }
    .pku-tile.photo-window .pw-content {
      position: relative;
      z-index: 1;
      display: flex;
      flex-direction: column;
      align-items: center;
      justify-content: center;
      text-align: center;
      width: 100%;
    }
    .pku-tile.photo-window .pw-badge {
      font-size: 0.7rem;
      letter-spacing: 0.12em;
      text-transform: uppercase;
      color: var(--gold-light);
      font-weight: 700;
      margin-bottom: 6px;
      text-align: center;
    }
    .pku-tile.photo-window .pw-name {
      font-family: var(--font-serif);
      font-size: 0.92rem;
      color: var(--white);
      font-weight: 600;
      line-height: 1.35;
      text-align: center;
    }

    .pku-num {
      font-family: var(--font-serif);
      font-size: 1.85rem;
      font-weight: 800;
      line-height: 1.1;
      font-variant-numeric: tabular-nums;
      background: var(--gold-grad-text);
      -webkit-background-clip: text;
      background-clip: text;
      -webkit-text-fill-color: transparent;
      filter: drop-shadow(0 2px 6px rgba(0,0,0,.6));
      margin-bottom: 6px;
    }
    .pku-lbl {
      font-size: .77rem;
      font-weight: 500;
      color: rgba(255,255,255,.88);
      line-height: 1.4;
    }



    .pku-sub {
      font-size: .73rem;
      color: rgba(255, 255, 255, .68);
      line-height: 1.4;
      margin-top: 5px;
    }

    /* ── 3. JOURNEY & TIMELINE (UFM Style Slide 9 & 10) ── */
    #journey { background: var(--navy-mid); }
    #journey .stitle { color: var(--white); }
    #journey .stitle span { color: var(--gold); }
    #journey .stext { color: rgba(255,255,255,.68); }
    .journey-grid {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 32px;
      align-items: start;
      margin-top: 40px;
    }
    @media(max-width: 900px) { .journey-grid { grid-template-columns: 1fr; } }

    /* Video Facade Sticky */
    .journey-video-sticky {
      position: sticky;
      top: 96px;
    }
    .video-facade {
      position: relative;
      border-radius: var(--radius-md);
      overflow: hidden;
      aspect-ratio: 16/9;
      background: #000;
      cursor: pointer;
      box-shadow: 0 12px 36px rgba(0,0,0,0.5);
      border: 1px solid rgba(201, 168, 76, 0.35);
    }
    .video-facade img { width: 100%; height: 100%; object-fit: cover; transition: transform .6s ease; }
    .video-facade:hover img { transform: scale(1.04); }
    .facade-overlay {
      position: absolute; inset: 0;
      background: radial-gradient(circle, rgba(11,30,61,0.2) 0%, rgba(6,14,30,0.85) 100%);
      transition: var(--t);
    }
    .video-facade:hover .facade-overlay { background: radial-gradient(circle, rgba(11,30,61,0.1) 0%, rgba(6,14,30,0.7) 100%); }
    .facade-play-btn {
      position: absolute; top: 50%; left: 50%; transform: translate(-50%, -50%);
      width: 68px; height: 68px; border-radius: 50%;
      background: var(--gold-grad);
      border: 2px solid #FFF;
      display: flex; align-items: center; justify-content: center;
      box-shadow: 0 0 30px rgba(255,215,0,0.6);
      cursor: pointer;
      transition: var(--t);
    }
    .video-facade:hover .facade-play-btn { transform: translate(-50%, -50%) scale(1.15); box-shadow: 0 0 45px rgba(255,215,0,0.9); }
    .facade-play-btn svg { width: 28px; height: 28px; color: var(--navy); margin-left: 4px; }
    .facade-badge {
      position: absolute; bottom: 12px; left: 14px;
      background: rgba(11, 30, 61, 0.85); backdrop-filter: blur(6px);
      padding: 4px 10px; border-radius: 12px; border: 1px solid rgba(201, 168, 76, 0.4);
      font-size: .73rem; color: var(--gold-light); font-weight: 600;
    }
    .video-sub-info {
      margin-top: 12px;
      display: flex; align-items: center; justify-content: space-between;
      color: rgba(255, 255, 255, 0.7); font-size: .78rem;
    }
    .video-sub-info .v-text { display: flex; align-items: center; gap: 6px; }
    .video-sub-info .v-tag {
      color: var(--gold-light); border: 1px solid rgba(201,168,76,0.3);
      padding: 2px 8px; border-radius: 10px; text-decoration: none;
    }
    .video-sub-info .v-tag:hover { background: var(--gold); color: var(--navy); }

    /* Khung ảnh lịch sử bên phải */
    .journey-timeline-side { display: flex; flex-direction: column; gap: 20px; }
    .tl-photo-display {
      position: relative;
      border-radius: var(--radius-md);
      overflow: hidden;
      box-shadow: 0 12px 36px rgba(0,0,0,0.4);
      border: 1px solid rgba(201,168,76,.3);
      background: var(--navy-deep);
    }
    .tl-photo-img-wrap {
      position: relative;
      width: 100%;
      height: 250px;
      overflow: hidden;
    }
    .tl-photo-img-wrap img {
      width: 100%;
      height: 100%;
      object-fit: cover;
      transition: opacity .35s ease, transform .5s ease;
    }
    .tl-photo-img-wrap img.fading { opacity: 0; transform: scale(1.04); }
    .tl-photo-overlay {
      position: absolute; inset: 0;
      background: linear-gradient(to top, rgba(6,14,30,.92) 0%, rgba(11,30,61,.3) 50%, transparent 100%);
      display: flex; flex-direction: column; justify-content: flex-end; padding: 18px;
    }
    .tl-photo-tag {
      display: inline-flex; align-items: center; gap: 4px;
      background: var(--gold-grad); color: var(--navy);
      font-size: .68rem; font-weight: 800; padding: 3px 9px; border-radius: 12px;
      margin-bottom: 6px; width: fit-content; text-transform: uppercase; letter-spacing: .05em;
    }
    .tl-photo-title { font-family: var(--font-serif); font-size: 1.15rem; font-weight: 700; color: var(--white); margin-bottom: 4px; }
    .tl-photo-caption { font-size: .8rem; color: rgba(255,255,255,.8); line-height: 1.45; }

    /* Timeline 5 mốc dọc */
    .timeline { display: flex; flex-direction: column; position: relative; }
    .timeline::before {
      content: ''; position: absolute; left: 20px; top: 8px; bottom: 8px; width: 2px;
      background: linear-gradient(to bottom, var(--gold), rgba(201,168,76,.15));
    }
    .tl-item {
      display: flex; gap: 16px; padding: 14px 16px; position: relative; cursor: pointer;
      border-radius: var(--radius-sm);
      border: 1px solid transparent; margin-bottom: 6px;
      transition: background .35s ease, border-color .35s ease, transform .35s cubic-bezier(.4,0,.2,1), box-shadow .35s ease, opacity .7s ease;
    }
    /* Hover luôn hoạt động mượt mà không bị reveal ghi đè */
    .tl-item:hover {
      background: linear-gradient(135deg, rgba(201,168,76,0.18) 0%, rgba(18,40,72,0.95) 100%);
      border-color: rgba(255,215,0,0.6);
      transform: scale(1.02) translateX(4px) !important;
      box-shadow: 0 8px 24px rgba(0,0,0,0.35);
    }
    .tl-item.active {
      background: linear-gradient(135deg, rgba(201,168,76,0.22) 0%, rgba(18,40,72,0.98) 100%);
      border-color: var(--gold);
      box-shadow: 0 6px 20px rgba(201,168,76,0.2);
    }
    .tl-item:nth-child(1) { transition-delay: 0.08s; }
    .tl-item:nth-child(2) { transition-delay: 0.16s; }
    .tl-item:nth-child(3) { transition-delay: 0.24s; }
    .tl-item:nth-child(4) { transition-delay: 0.32s; }
    .tl-item:nth-child(5) { transition-delay: 0.40s; }

    .tl-dot {
      flex-shrink: 0; width: 38px; height: 38px; border-radius: 50%; background: var(--navy-mid);
      border: 2px solid var(--gold); display: flex; align-items: center; justify-content: center;
      z-index: 1; transition: var(--t);
    }
    .tl-dot::after { content: ''; width: 12px; height: 12px; border-radius: 50%; background: var(--gold); transition: var(--t); }
    .tl-item:hover .tl-dot, .tl-item.active .tl-dot {
      background: var(--gold); transform: scale(1.12); box-shadow: 0 0 16px rgba(255,215,0,.6);
    }
    .tl-item:hover .tl-dot::after, .tl-item.active .tl-dot::after { background: var(--navy); }
    .tl-body { padding-top: 2px; flex: 1; }
    .tl-year-row { display: flex; align-items: center; justify-content: space-between; margin-bottom: 2px; }
    .tl-year { font-size: .76rem; letter-spacing: .12em; color: var(--gold); font-weight: 800; }
    .tl-view-hint { font-size: .7rem; color: rgba(255,255,255,.5); transition: var(--t); }
    .tl-title { font-family: var(--font-serif); font-size: .98rem; font-weight: 700; color: var(--white); margin-bottom: 3px; }
    .tl-item.active .tl-title { color: var(--gold-light); }
    .tl-desc { font-size: .78rem; color: rgba(255,255,255,.65); line-height: 1.5; }
    .tl-detail-btn {
      display: inline-flex; align-items: center; gap: 4px; margin-top: 6px;
      font-size: .72rem; font-weight: 600; color: var(--gold-light); background: rgba(201,168,76,.15);
      padding: 3px 9px; border-radius: 10px; border: 1px solid rgba(201,168,76,.3); cursor: pointer; transition: var(--t);
    }
    .tl-detail-btn:hover { background: var(--gold); color: var(--navy); }

    /* ── 4. IDENTITY ── */
    #identity { background: var(--off-white); }
    .id-layout { display: grid; grid-template-columns: 1fr 1.3fr; gap: 48px; align-items: center; margin-top: 40px; }
    @media(max-width: 860px) { .id-layout { grid-template-columns: 1fr; gap: 30px; } }
    .id-logo-side { display: flex; align-items: center; justify-content: center; }
    .id-logo-side img { width: clamp(200px, 22vw, 300px); object-fit: contain; filter: drop-shadow(0 10px 30px rgba(201,168,76,.25)); }
    .id-para { font-size: .92rem; line-height: 1.8; color: var(--text-muted); margin-bottom: 12px; }
    .gift-blocks { display: grid; grid-template-columns: repeat(3, 1fr); gap: 16px; margin-top: 36px; }
    @media(max-width: 768px) { .gift-blocks { grid-template-columns: 1fr; } }
    .gblock {
      background: var(--white); border-radius: var(--radius-md); padding: 22px 16px; text-align: center;
      border: 1px solid rgba(201,168,76,.2); box-shadow: var(--shadow-card); transition: var(--t); position: relative; overflow: hidden;
    }
    .gblock::before { content: ''; position: absolute; bottom: 0; left: 0; right: 0; height: 3px; background: var(--gold-grad); }
    .gblock:hover { transform: translateY(-4px); box-shadow: var(--shadow-hover); }
    .gblock-icon { font-size: 1.8rem; margin-bottom: 8px; }
    .gblock-title { font-family: var(--font-serif); font-size: .92rem; font-weight: 700; color: var(--navy); margin-bottom: 4px; }
    .gblock-desc { font-size: .78rem; color: var(--text-muted); line-height: 1.5; }

    /* ── 5. ALUMNI & COMMUNITY MARQUEE ── */
    #alumni { background: var(--white); }
    .alumni-head { display: flex; align-items: flex-end; justify-content: space-between; margin-bottom: 36px; flex-wrap: wrap; gap: 16px; }
    .alumni-gallery { display: grid; grid-template-columns: repeat(4, 1fr); grid-template-rows: auto auto; gap: 12px; }
    @media(max-width: 860px) { .alumni-gallery { grid-template-columns: repeat(2, 1fr); } }
    .acard {
      border-radius: var(--radius-sm); overflow: hidden; background: var(--off-white);
      box-shadow: var(--shadow-card); transition: var(--t); position: relative; cursor: pointer;
    }
    .acard:hover { transform: translateY(-6px) scale(1.02); box-shadow: var(--shadow-hover); }
    .acard.feat { grid-column: span 2; grid-row: span 2; }
    .acard img { height: 100%; min-height: 160px; }
    .acard.feat img { min-height: 330px; }
    .a-overlay {
      position: absolute; inset: 0; background: linear-gradient(to top, rgba(11,30,61,.85) 0%, transparent 55%);
      display: flex; align-items: flex-end; padding: 14px; opacity: 0; transition: var(--t);
    }
    .acard:hover .a-overlay { opacity: 1; }
    .a-cap { color: var(--white); font-size: .84rem; font-weight: 600; line-height: 1.35; }

    /* DẢI LỜI NHẮN TỰ ĐỘNG CHẠY (Pure CSS 60 FPS Infinite Marquee - Slide 12) */
    .wishes-marquee-section {
      margin-top: 48px;
      padding-top: 28px;
      border-top: 1px solid rgba(201,168,76,.2);
      overflow: hidden;
    }
    .wishes-marquee-header {
      display: flex; align-items: center; justify-content: space-between; margin-bottom: 16px;
    }
    .wishes-marquee-header h4 {
      font-family: var(--font-serif); font-size: 1.05rem; color: var(--navy); font-weight: 700;
    }
    .wishes-marquee-header span {
      font-size: .76rem; color: var(--gold); font-weight: 600; text-transform: uppercase; letter-spacing: .06em;
    }
    .marquee-container {
      width: 100%;
      overflow: hidden;
      position: relative;
      mask-image: linear-gradient(to right, transparent 0%, black 6%, black 94%, transparent 100%);
      -webkit-mask-image: linear-gradient(to right, transparent 0%, black 6%, black 94%, transparent 100%);
    }
    .marquee-track {
      display: flex;
      gap: 16px;
      width: max-content;
      animation: marqueeRun 40s linear infinite;
      will-change: transform;
    }
    .marquee-container:hover .marquee-track {
      animation-play-state: paused;
    }
    @keyframes marqueeRun {
      0% { transform: translate3d(0, 0, 0); }
      100% { transform: translate3d(-50%, 0, 0); }
    }
    .wish-card {
      width: 290px;
      flex-shrink: 0;
      background: var(--off-white);
      border: 1px solid rgba(201,168,76,.25);
      border-radius: var(--radius-sm);
      padding: 16px;
      box-shadow: var(--shadow-card);
      transition: var(--t);
      position: relative;
    }
    .wish-card:hover {
      border-color: var(--gold);
      transform: translateY(-4px);
      box-shadow: var(--shadow-hover);
      background: var(--white);
    }
    .wish-quote-icon {
      font-family: var(--font-serif);
      font-size: 1.8rem;
      line-height: 1;
      color: var(--gold);
      margin-bottom: 4px;
    }
    .wish-text {
      font-size: .8rem;
      line-height: 1.55;
      color: var(--text-dark);
      font-style: italic;
      margin-bottom: 12px;
    }
    .wish-author-row {
      display: flex;
      align-items: center;
      gap: 10px;
    }
    .wish-avatar {
      width: 32px;
      height: 32px;
      border-radius: 50%;
      background: var(--navy);
      color: var(--gold-light);
      display: flex;
      align-items: center;
      justify-content: center;
      font-size: .75rem;
      font-weight: 700;
      flex-shrink: 0;
    }
    .wish-name {
      font-size: .78rem;
      font-weight: 700;
      color: var(--navy);
      line-height: 1.2;
    }
    .wish-role {
      font-size: .7rem;
      color: var(--text-muted);
      line-height: 1.2;
    }

    /* ── 6. EVENTS ── */
    #events { background: var(--off-white); }
    .events-grid { display: grid; grid-template-columns: 1.1fr 1fr; gap: 36px; align-items: start; margin-top: 40px; }
    @media(max-width: 860px) { .events-grid { grid-template-columns: 1fr; } }
    .ev-list { display: flex; flex-direction: column; gap: 16px; }
    .ev-card {
      background: var(--white); border-radius: var(--radius-sm); padding: 18px 20px;
      border-left: 4px solid var(--gold); box-shadow: var(--shadow-card); transition: var(--t); cursor: pointer;
    }
    .ev-card:hover { transform: translateX(6px); box-shadow: var(--shadow-hover); }
    .ev-date { font-size: .72rem; letter-spacing: .1em; text-transform: uppercase; color: var(--gold); font-weight: 700; margin-bottom: 4px; }
    .ev-title { font-family: var(--font-serif); font-size: 1rem; font-weight: 700; color: var(--navy); margin-bottom: 4px; }
    .ev-loc { font-size: .78rem; color: var(--text-muted); display: flex; align-items: center; gap: 4px; }
    .upcoming-box {
      background: var(--navy); border-radius: var(--radius-md); padding: 28px 24px; color: var(--white);
      border: 1px solid rgba(201,168,76,.3);
    }
    .up-title-main { font-family: var(--font-serif); font-size: 1.1rem; color: var(--gold-light); margin-bottom: 18px; font-weight: 700; }
    .up-list { display: flex; flex-direction: column; gap: 14px; }
    .up-item {
      display: flex; gap: 14px; align-items: center; padding: 10px 12px;
      background: rgba(255,255,255,.05); border-radius: var(--radius-sm); border: 1px solid rgba(201,168,76,.15);
      transition: var(--t); cursor: pointer;
    }
    .up-item:hover { background: rgba(201,168,76,.12); border-color: var(--gold); }
    .up-date { text-align: center; flex-shrink: 0; width: 44px; }
    .up-date .day { font-size: 1.3rem; font-weight: 800; color: var(--gold-light); line-height: 1; font-family: var(--font-serif); }
    .up-date .mon { font-size: .65rem; color: rgba(255,255,255,.6); text-transform: uppercase; }
    .up-info { flex: 1; }
    .up-info .up-title { font-size: .84rem; font-weight: 600; color: var(--white); line-height: 1.3; }
    .up-info .up-loc { font-size: .72rem; color: rgba(255,255,255,.5); margin-top: 2px; }
    .up-arrow { color: var(--gold); font-size: .9rem; transition: var(--t); }
    .up-item:hover .up-arrow { transform: translateX(3px); }

    /* ── 7. MEDIA ── */
    #media { background: var(--white); }
    .media-grid { display: grid; grid-template-columns: 1.15fr 1fr; gap: 28px; margin-top: 36px; }
    @media(max-width: 860px) { .media-grid { grid-template-columns: 1fr; } }
    .med-feat {
      border-radius: var(--radius-md); overflow: hidden; position: relative;
      min-height: 310px; box-shadow: var(--shadow-card); cursor: pointer;
    }
    .med-feat img { height: 100%; min-height: 310px; transition: transform .5s ease; }
    .med-feat:hover img { transform: scale(1.04); }
    .med-f-overlay {
      position: absolute; inset: 0; background: linear-gradient(to top, rgba(11,30,61,.9) 0%, transparent 55%);
      display: flex; flex-direction: column; justify-content: flex-end; padding: 20px;
    }
    .med-badge {
      display: inline-flex; align-items: center; gap: 4px; background: var(--gold); color: var(--navy);
      font-size: .68rem; font-weight: 700; padding: 3px 8px; border-radius: 16px; margin-bottom: 8px; width: fit-content;
    }
    .med-ftitle { font-family: var(--font-serif); font-size: 1.05rem; color: var(--white); line-height: 1.35; font-weight: 700; }
    .med-list { display: flex; flex-direction: column; gap: 12px; }
    .med-item {
      display: flex; gap: 12px; align-items: flex-start; background: var(--white); border-radius: var(--radius-sm);
      padding: 12px; box-shadow: var(--shadow-card); cursor: pointer; transition: var(--t);
    }
    .med-item:hover { transform: translateX(5px); box-shadow: var(--shadow-hover); }
    .med-thumb { flex-shrink: 0; width: 78px; height: 58px; border-radius: 6px; overflow: hidden; background: var(--off-white); }
    .med-thumb img { width: 100%; height: 100%; }
    .med-body { flex: 1; }
    .med-src { font-size: .65rem; letter-spacing: .08em; text-transform: uppercase; color: var(--gold); font-weight: 600; margin-bottom: 2px; }
    .med-title { font-size: .84rem; font-weight: 600; color: var(--navy); line-height: 1.35; }
    .med-date { font-size: .7rem; color: var(--text-muted); margin-top: 2px; }

    /* ── 8. PUBLICATIONS ── */
    #publications { background: var(--navy); }
    #publications .stitle { color: var(--white); }
    #publications .stitle span { color: var(--gold); }
    #publications .stext { color: rgba(255,255,255,.6); }
    .pub-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 16px; margin-top: 36px; }
    @media(max-width: 900px) { .pub-grid { grid-template-columns: repeat(2, 1fr); } }
    @media(max-width: 500px) { .pub-grid { grid-template-columns: 1fr; } }
    .pub-card {
      background: rgba(255,255,255,.05); border: 1px solid rgba(201,168,76,.2); border-radius: var(--radius-sm);
      overflow: hidden; cursor: pointer; transition: var(--t);
    }
    .pub-card:hover { border-color: var(--gold); transform: translateY(-6px) rotate(-1deg); box-shadow: 0 18px 48px rgba(0,0,0,.4); }
    .pub-img { height: 210px; position: relative; }
    .pub-img img { height: 100%; }
    .pub-img::after { content: ''; position: absolute; inset: 0; background: linear-gradient(to top, rgba(11,30,61,.55), transparent 55%); }
    .pub-body { padding: 15px; }
    .pub-type { font-size: .68rem; letter-spacing: .1em; text-transform: uppercase; color: var(--gold); margin-bottom: 4px; }
    .pub-title { font-family: var(--font-serif); font-size: .88rem; color: var(--white); font-weight: 700; line-height: 1.35; }
    .pub-dl { display: flex; align-items: center; gap: 6px; margin-top: 8px; font-size: .74rem; color: rgba(255,255,255,.4); transition: var(--t); }
    .pub-card:hover .pub-dl { color: var(--gold); }
    .pub-dl svg { width: 12px; height: 12px; }

    /* ── 9. MEMORIES (Slide 14 - Wuhan University Reference Layout) ── */
    #memories { background: var(--white); }
    .whu-layout {
      display: grid;
      grid-template-columns: 310px 1fr;
      gap: 18px;
      margin-top: 32px;
      align-items: stretch;
    }
    @media(max-width: 960px) {
      .whu-layout { grid-template-columns: 1fr; }
    }

    /* Cột trái: Khung truyền thống xanh lục đặc trưng WHU Style */
    .whu-articles-card {
      background: linear-gradient(180deg, #004D47 0%, #003632 100%);
      border: 1.5px solid rgba(201,168,76,0.4);
      border-radius: var(--radius-sm);
      padding: 24px 20px;
      color: var(--white);
      display: flex;
      flex-direction: column;
      justify-content: space-between;
      position: relative;
      overflow: hidden;
      box-shadow: var(--shadow-card);
    }
    /* Hoa văn kiến trúc line-art ở chân khung */
    .whu-articles-card::after {
      content: '';
      position: absolute;
      bottom: 0; left: 0; right: 0;
      height: 110px;
      background: url('data:image/svg+xml;utf8,<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 300 100" fill="none" stroke="rgba(201,168,76,0.18)" stroke-width="1.2"><path d="M10,95 L10,65 L30,65 L30,45 L150,15 L270,45 L270,65 L290,65 L290,95"/><path d="M50,95 L50,65 M90,95 L90,65 M130,95 L130,65 M170,95 L170,65 M210,95 L210,65 M250,95 L250,65"/></svg>') bottom center no-repeat;
      pointer-events: none;
      opacity: 0.85;
    }
    .whu-art-list {
      display: flex;
      flex-direction: column;
      gap: 18px;
      position: relative;
      z-index: 1;
    }
    .whu-art-item {
      cursor: pointer;
      transition: var(--t);
      padding-bottom: 12px;
      border-bottom: 1px solid rgba(201,168,76,0.2);
    }
    .whu-art-item:last-child { border-bottom: none; }
    .whu-art-item:hover { transform: translateX(4px); }
    .whu-art-tag {
      font-size: 0.72rem;
      color: var(--gold-light);
      letter-spacing: 0.05em;
      margin-bottom: 5px;
      display: inline-block;
    }
    .whu-art-title {
      font-family: var(--font-serif);
      font-size: 0.88rem;
      line-height: 1.45;
      color: rgba(255,255,255,0.92);
      font-weight: 600;
    }
    .whu-art-item:hover .whu-art-title { color: #FFD700; }
    .whu-more-btn {
      display: inline-flex;
      align-items: center;
      justify-content: center;
      gap: 6px;
      margin-top: 18px;
      padding: 8px 16px;
      border: 1px solid var(--gold);
      border-radius: 4px;
      color: var(--gold-light);
      font-size: 0.8rem;
      font-weight: 600;
      letter-spacing: 0.04em;
      background: rgba(201,168,76,0.12);
      transition: var(--t);
      position: relative;
      z-index: 1;
      width: 100%;
    }
    .whu-more-btn:hover {
      background: var(--gold-grad);
      color: var(--navy);
      border-color: var(--gold);
    }

    /* Vùng bên phải: Lưới ảnh bám sát Slide 14 */
    .whu-visual-col {
      display: grid;
      grid-template-columns: 240px 1fr;
      gap: 14px;
    }
    @media(max-width: 720px) {
      .whu-visual-col { grid-template-columns: 1fr; }
    }

    /* Ảnh poster dọc nghệ thuật (Trái của visual group) */
    .whu-poster-tall {
      border-radius: var(--radius-sm);
      overflow: hidden;
      position: relative;
      cursor: pointer;
      box-shadow: var(--shadow-card);
      min-height: 420px;
    }
    .whu-poster-tall img { height: 100%; object-fit: cover; transition: transform .6s ease; }
    .whu-poster-tall:hover img { transform: scale(1.05); }
    .whu-poster-overlay {
      position: absolute; inset: 0;
      background: linear-gradient(to top, rgba(6,14,30,0.92) 0%, rgba(11,30,61,0.2) 50%, transparent 100%);
      display: flex; flex-direction: column; justify-content: flex-end; padding: 18px;
    }
    .whu-poster-badge {
      display: inline-flex; align-items: center; gap: 5px;
      background: var(--gold-grad); color: var(--navy);
      font-size: 0.65rem; font-weight: 800; padding: 3px 8px; border-radius: 12px;
      margin-bottom: 6px; width: fit-content; text-transform: uppercase;
    }
    .whu-poster-title {
      font-family: var(--font-serif);
      font-size: 0.95rem;
      font-weight: 700;
      color: var(--white);
      line-height: 1.35;
    }

    /* Nhóm ảnh bên phải (Gồm ảnh ngang trên và 2 ô dưới) */
    .whu-sub-grid {
      display: flex;
      flex-direction: column;
      gap: 14px;
    }
    /* Ảnh ngang trên (COVER KỶ NIỆM) */
    .whu-cover-wide {
      border-radius: var(--radius-sm);
      overflow: hidden;
      position: relative;
      cursor: pointer;
      box-shadow: var(--shadow-card);
      height: 205px;
    }
    .whu-cover-wide img { width: 100%; height: 100%; object-fit: cover; transition: transform .6s ease; }
    .whu-cover-wide:hover img { transform: scale(1.04); }
    .whu-cover-overlay {
      position: absolute; inset: 0;
      background: linear-gradient(to top, rgba(6,14,30,0.9) 0%, transparent 60%);
      display: flex; flex-direction: column; justify-content: flex-end; padding: 16px;
    }
    .whu-cover-tag {
      display: inline-flex; align-items: center; gap: 4px;
      background: #D32F2F; color: #FFF;
      font-size: 0.62rem; font-weight: 800; padding: 2px 7px; border-radius: 4px;
      margin-bottom: 4px; width: fit-content; letter-spacing: 0.05em;
    }
    .whu-cover-title {
      font-family: var(--font-serif);
      font-size: 0.96rem;
      font-weight: 700;
      color: var(--white);
      line-height: 1.3;
    }

    /* 2 ô phía dưới: 1 ô ảnh kỷ vật + 1 ô giấy ấm mạng xã hội Alumni */
    .whu-bottom-row {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 14px;
      height: 200px;
    }
    @media(max-width: 540px) {
      .whu-bottom-row { grid-template-columns: 1fr; height: auto; }
    }

    .whu-card-square {
      border-radius: var(--radius-sm);
      overflow: hidden;
      position: relative;
      cursor: pointer;
      box-shadow: var(--shadow-card);
      background: var(--navy-deep);
    }
    .whu-card-square img { width: 100%; height: 100%; object-fit: cover; transition: transform .5s ease; }
    .whu-card-square:hover img { transform: scale(1.05); }
    .whu-card-square .overlay {
      position: absolute; inset: 0;
      background: linear-gradient(to top, rgba(6,14,30,0.9) 0%, transparent 60%);
      display: flex; flex-direction: column; justify-content: flex-end; padding: 12px;
    }
    .whu-card-square .cap {
      color: var(--white); font-size: 0.78rem; font-weight: 600; line-height: 1.35;
    }

    /* Khung giấy ấm parchment kết nối HUB Alumni & Mạng xã hội */
    .whu-card-alumni {
      border-radius: var(--radius-sm);
      background: #FAF3E8;
      border: 1px solid rgba(201,168,76,0.35);
      padding: 16px 14px;
      display: flex;
      flex-direction: column;
      justify-content: space-between;
      box-shadow: var(--shadow-card);
      position: relative;
      overflow: hidden;
    }
    .whu-alumni-head {
      font-family: var(--font-serif);
      font-size: 0.85rem;
      font-weight: 700;
      color: #5C3810;
      margin-bottom: 8px;
      display: flex; align-items: center; gap: 6px;
    }
    .whu-social-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 8px;
    }
    .whu-social-icon {
      background: rgba(201,168,76,0.18);
      border: 1px solid rgba(186,128,30,0.3);
      border-radius: 6px;
      display: flex;
      flex-direction: column;
      align-items: center;
      justify-content: center;
      padding: 6px 4px;
      text-align: center;
      transition: var(--t);
      text-decoration: none;
      color: #4A2E0B;
    }
    .whu-social-icon:hover {
      background: var(--navy);
      color: var(--gold-light);
      border-color: var(--navy);
      transform: translateY(-2px);
    }
    .whu-social-icon svg { width: 16px; height: 16px; margin-bottom: 2px; }
    .whu-social-icon span { font-size: 0.62rem; font-weight: 600; line-height: 1.1; }

    /* Quotes slider */
    .quotes-box {
      margin-top: 36px;
      background: linear-gradient(135deg, rgba(11,30,61,0.04) 0%, rgba(201,168,76,0.06) 100%);
      border: 1px solid rgba(201,168,76,0.25);
      border-radius: var(--radius-md);
      padding: 24px;
      position: relative;
    }
    .q-slider { overflow: hidden; position: relative; }
    .q-track { display: flex; transition: transform .5s cubic-bezier(.4,0,.2,1); }
    .q-slide { min-width: 100%; box-sizing: border-box; text-align: center; padding: 8px 16px; }
    .q-text { font-family: var(--font-serif); font-size: 1.05rem; font-style: italic; color: var(--navy); line-height: 1.6; margin-bottom: 10px; }
    .q-author { font-size: .8rem; font-weight: 600; color: var(--gold); }
    .q-nav { display: flex; justify-content: center; gap: 8px; margin-top: 14px; }
    .q-dot { width: 8px; height: 8px; border-radius: 50%; background: rgba(11,30,61,.2); cursor: pointer; transition: var(--t); }
    .q-dot.active { background: var(--gold); transform: scale(1.3); }

    /* ── 10. CÙNG VIẾT TIẾP HÀNH TRÌNH ── */
    #contribute { background: var(--navy-mid); }
    #contribute .stitle { color: var(--white); }
    #contribute .stitle span { color: var(--gold); }
    #contribute .stext { color: rgba(255,255,255,.68); }
    .contrib-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 32px; margin-top: 40px; }
    @media(max-width: 860px) { .contrib-grid { grid-template-columns: 1fr; } }
    .cbox {
      background: rgba(255,255,255,.05); border: 1px solid rgba(201,168,76,.22);
      border-radius: var(--radius-md); padding: 30px 24px; transition: var(--t);
    }
    .cbox:hover { border-color: rgba(255,215,0,.45); background: rgba(255,255,255,.08); }
    .cbox-title { font-family: var(--font-serif); font-size: 1.15rem; font-weight: 700; color: var(--white); margin-bottom: 6px; }
    .cbox-sub { font-size: .8rem; color: rgba(255,255,255,.6); line-height: 1.5; margin-bottom: 20px; }
    .cform { display: flex; flex-direction: column; gap: 12px; }
    .fgroup { display: flex; flex-direction: column; gap: 4px; }
    .fgroup label { font-size: .74rem; font-weight: 600; color: rgba(255,255,255,.75); letter-spacing: .04em; }
    .finput, .fselect, .ftextarea {
      background: rgba(255,255,255,.08); border: 1px solid rgba(201,168,76,.25);
      border-radius: var(--radius-sm); padding: 10px 14px; color: var(--white);
      font-size: .84rem; font-family: var(--font-sans); outline: none; transition: var(--t);
    }
    .finput:focus, .fselect:focus, .ftextarea:focus {
      border-color: var(--gold); background: rgba(255,255,255,.12);
      box-shadow: 0 0 0 3px rgba(201,168,76,.2);
    }
    .fselect option { background: var(--navy); color: var(--white); }
    .ftextarea { resize: vertical; min-height: 80px; }
    .btn-submit {
      background: var(--gold-grad); color: var(--navy); font-weight: 700; font-size: .88rem;
      padding: 12px 24px; border-radius: var(--radius-xl); border: none; cursor: pointer;
      letter-spacing: .04em; transition: var(--t); margin-top: 6px;
      box-shadow: 0 6px 20px rgba(201,168,76,.3);
    }
    .btn-submit:hover { transform: translateY(-2px); box-shadow: 0 12px 38px rgba(201,168,76,.45); }
    .btn-submit:active { transform: translateY(0); }

    /* ── BACK TO TOP ── */
    #btt {
      position: fixed; bottom: 26px; right: 26px; width: 44px; height: 44px; border-radius: 50%;
      background: var(--gold-grad); color: var(--navy); display: flex; align-items: center; justify-content: center;
      cursor: pointer; z-index: 999; box-shadow: 0 6px 20px rgba(201,168,76,.3); opacity: 0; transform: translateY(20px);
      transition: var(--t); border: none;
    }
    #btt.visible { opacity: 1; transform: translateY(0); }
    #btt:hover { transform: translateY(-3px) scale(1.08); box-shadow: 0 10px 30px rgba(201,168,76,.5); }
    #btt svg { width: 18px; height: 18px; }

    /* ── MODALS (Timeline Detail & Lightbox) ── */
    .hub-modal {
      position: fixed; inset: 0; z-index: 9999;
      background: rgba(6,14,30,.85); backdrop-filter: blur(8px);
      display: flex; align-items: center; justify-content: center; padding: 20px;
      opacity: 0; pointer-events: none; transition: opacity .3s ease;
    }
    .hub-modal.open { opacity: 1; pointer-events: auto; }
    .modal-box {
      background: var(--navy-mid); border: 1px solid rgba(201,168,76,.35);
      border-radius: var(--radius-md); max-width: 680px; width: 100%; overflow: hidden;
      box-shadow: 0 24px 60px rgba(0,0,0,.6); transform: scale(.95); transition: transform .3s ease;
      position: relative;
    }
    .hub-modal.open .modal-box { transform: scale(1); }
    .modal-close {
      position: absolute; top: 14px; right: 14px; z-index: 10;
      width: 34px; height: 34px; border-radius: 50%;
      background: rgba(0,0,0,.6); color: var(--white); border: 1px solid rgba(255,255,255,.2);
      cursor: pointer; display: flex; align-items: center; justify-content: center;
      font-size: 1.1rem; transition: var(--t);
    }
    .modal-close:hover { background: var(--gold); color: var(--navy); }
    .modal-img-wrap { width: 100%; height: 260px; overflow: hidden; position: relative; }
    .modal-img-wrap img { width: 100%; height: 100%; object-fit: cover; }
    .modal-body { padding: 24px; color: var(--white); }
    .modal-tag { color: var(--gold); font-size: .75rem; letter-spacing: .1em; text-transform: uppercase; font-weight: 700; margin-bottom: 6px; }
    .modal-title { font-family: var(--font-serif); font-size: 1.3rem; font-weight: 700; color: var(--white); margin-bottom: 12px; }
    .modal-desc { font-size: .88rem; color: rgba(255,255,255,.8); line-height: 1.75; }

    /* Lightbox Modal */
    .lightbox-box {
      max-width: 900px; width: 100%; max-height: 90vh;
      display: flex; flex-direction: column; align-items: center;
    }
    .lightbox-img-wrap {
      width: 100%; max-height: 75vh; overflow: hidden; border-radius: var(--radius-sm);
      box-shadow: 0 20px 60px rgba(0,0,0,.8); border: 1px solid rgba(201,168,76,.3);
    }
    .lightbox-img-wrap img { width: 100%; height: 100%; max-height: 75vh; object-fit: contain; background: #000; }
    .lightbox-title { color: var(--white); font-size: .95rem; margin-top: 12px; font-weight: 600; text-align: center; font-family: var(--font-serif); }