:root {
    /* Bảng màu lấy cảm hứng từ vật liệu bán dẫn */
    --silicon-900: #10151c;
    --silicon-800: #1b2430;
    --silicon-700: #2a3646;
    --silicon-500: #55677d;
    --silicon-300: #9aa9bc;
    --silicon-100: #eef2f7;
    --silicon-50:  #f7f9fc;

    --copper: #b06f3c;
    --copper-light: #d68f5c;
    --amber: #f0a500;
    --amber-soft: #ffe9b8;
    --teal: #17879e;

    --bg: #ffffff;
    --text: #1b2430;
    --text-muted: #55677d;
    --border: #e2e8f0;

    --radius: 10px;
    --shadow-sm: 0 1px 3px rgba(16, 21, 28, .08);
    --shadow-md: 0 6px 20px rgba(16, 21, 28, .10);
    --container: 1160px;
}
/* ===== Khung video giới thiệu ===== */
.video-vien {
    max-width: 900px; /* giới hạn bề ngang */
    margin: 32px auto; /* căn giữa khối */
    position: relative;
    width: 100%;
    padding-top: 56.25%; /* tỷ lệ 16:9 -> 9/16 = 56.25% */
    background: #0f1418;
    border: 1px solid #b87333; /* viền đồng */
    border-radius: 8px;
    overflow: hidden;
    box-shadow: 0 6px 24px rgba(0, 0, 0, .25);
}
/* ===== Khung video giới thiệu (bản to hơn) ===== */
.video-vien {
    max-width: 1400px; /* to hơn nhiều so với 900px */
    width: 100%;
    margin: 32px auto;
    position: relative;
    padding-top: 56.25%; /* 16:9 */
    background: #000;
    border: 1px solid #b87333;
    border-radius: 8px;
    overflow: hidden;
    box-shadow: 0 6px 24px rgba(0, 0, 0, .25);
}

/* ===== Khung video giới thiệu ===== */
.video-vien {
    max-width: 900px; /* kích thước ban đầu */
    width: 100%;
    margin: 32px auto;
    position: relative;
    padding-top: 56.25%; /* 16:9 */
    background: #000;
    border: 1px solid #b87333;
    border-radius: 8px;
    overflow: hidden;
    box-shadow: 0 6px 24px rgba(0, 0, 0, .25);
    transition: max-width .45s ease, box-shadow .45s ease;
}

    /* Trạng thái đang phát: phóng to */
    .video-vien.dang-phat {
        max-width: 1400px;
        box-shadow: 0 10px 36px rgba(0, 0, 0, .35);
    }

    .video-vien video {
        position: absolute;
        top: 0;
        left: 0;
        width: 100%;
        height: 100%;
        display: block;
        object-fit: cover;
        background: #000;
    }

        .video-vien video:fullscreen,
        .video-vien video:-webkit-full-screen,
        .video-vien video:-moz-full-screen,
        .video-vien video:-ms-fullscreen {
            object-fit: contain;
            border-radius: 0;
        }

@media (max-width: 768px) {
    .video-vien {
        margin: 20px auto;
        border-radius: 6px;
    }

}


* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
    margin: 0;
    font-family: 'IBM Plex Sans', system-ui, -apple-system, 'Segoe UI', sans-serif;
    color: var(--text);
    background: var(--bg);
    line-height: 1.65;
    -webkit-font-smoothing: antialiased;
}

.container { max-width: var(--container); margin: 0 auto; padding: 0 24px; }

a { color: var(--copper); text-decoration: none; transition: color .15s; }
a:hover { color: var(--copper-light); }

h1, h2, h3, h4 { line-height: 1.25; color: var(--silicon-900); font-weight: 700; }

code, .mono { font-family: 'IBM Plex Mono', monospace; }

/* ===================== HEADER ===================== */
.site-header {
    position: sticky; top: 0; z-index: 50;
    background: rgba(255, 255, 255, .92);
    backdrop-filter: saturate(180%) blur(8px);
    border-bottom: 1px solid var(--border);
}
.header-inner { display: flex; align-items: center; justify-content: space-between; height: 72px; }
.brand { display: flex; align-items: center; gap: 12px; color: var(--silicon-900); }
.brand-mark { color: var(--copper); display: inline-flex; }
.brand-logo {
    height: 48px;
    width: 48px;
    object-fit: contain;
    display: block;
}
.anh-gallery {
    display: flex;
    flex-direction: column;
    gap: 16px;
    margin: 0 0 18px;
}

.anh-noidung {
    max-width: 100%;
    height: auto;
    border-radius: 10px;
    display: block;
}
.noidung-canhdeu {
    text-align: justify;
    text-justify: inter-word;
}
.anh-noidung {
    max-width: 100%;
    height: auto;
    border-radius: 10px;
    display: block;
    margin: 0 0 18px;
}
.brand-text strong { display: block; font-size: 1rem; line-height: 1.2; }
.brand-text small { display: block; font-size: .72rem; color: var(--text-muted); letter-spacing: .3px; }

.main-nav { display: flex; align-items: center; gap: 4px; }
.main-nav a {
    color: var(--silicon-700); font-weight: 500; font-size: .93rem;
    padding: 8px 14px; border-radius: 8px;
}
.main-nav a:hover { background: var(--silicon-100); color: var(--silicon-900); }
.main-nav .nav-cta {
    background: var(--silicon-900); color: #fff; margin-left: 6px;
}
.main-nav .nav-cta:hover { background: var(--copper); color: #fff; }

.nav-toggle { display: none; flex-direction: column; gap: 5px; background: none; border: 0; cursor: pointer; padding: 8px; }
.nav-toggle span { width: 24px; height: 2px; background: var(--silicon-900); border-radius: 2px; }

/* ===================== HERO ===================== */
.hero {
    position: relative; overflow: hidden;
    background: linear-gradient(135deg, var(--silicon-900), var(--silicon-700) 70%);
    color: #fff; padding: 80px 0 90px;
}
.hero-grid-bg {
    position: absolute; inset: 0; opacity: .16;
    background-image:
        linear-gradient(rgba(240,165,0,.5) 1px, transparent 1px),
        linear-gradient(90deg, rgba(240,165,0,.5) 1px, transparent 1px);
    background-size: 44px 44px;
    -webkit-mask-image: radial-gradient(circle at 70% 30%, #000 0%, transparent 65%);
    mask-image: radial-gradient(circle at 70% 30%, #000 0%, transparent 65%);
}
.hero .container { position: relative; z-index: 1; display: grid; grid-template-columns: 1.15fr .85fr; gap: 48px; align-items: center; }
.hero h1 { color: #fff; font-size: 2.5rem; margin: 0 0 16px; }
.hero .lead { font-size: 1.12rem; color: var(--silicon-100); max-width: 46ch; }
.hero-eyebrow {
    display: inline-block; font-family: 'IBM Plex Mono', monospace; font-size: .8rem;
    letter-spacing: 2px; text-transform: uppercase; color: var(--amber); margin-bottom: 16px;
}
.hero-actions { margin-top: 28px; display: flex; gap: 12px; flex-wrap: wrap; }

/* Sơ đồ wafer SVG bên phải hero */
.wafer { width: 100%; max-width: 340px; margin: 0 auto; display: block; }
.wafer .die { fill: rgba(240,165,0,.14); stroke: var(--amber); stroke-width: .6; }
.wafer .die.on { animation: dieGlow 3.2s ease-in-out infinite; }
@keyframes dieGlow {
    0%, 100% { fill: rgba(240,165,0,.10); }
    50%      { fill: rgba(240,165,0,.55); }
}

/* ===================== BUTTONS ===================== */
.btn {
    display: inline-flex; align-items: center; gap: 8px;
    padding: 11px 22px; border-radius: 8px; font-weight: 600; font-size: .95rem;
    border: 1px solid transparent; cursor: pointer; transition: all .15s;
}
.btn-primary { background: var(--amber); color: var(--silicon-900); }
.btn-primary:hover { background: #ffb92e; color: var(--silicon-900); }
.btn-ghost { background: transparent; color: #fff; border-color: rgba(255,255,255,.4); }
.btn-ghost:hover { background: rgba(255,255,255,.12); color: #fff; }
.btn-dark { background: var(--silicon-900); color: #fff; }
.btn-dark:hover { background: var(--copper); color: #fff; }

/* ===================== SECTIONS ===================== */
.section { padding: 72px 0; }
.section.alt { background: var(--silicon-50); }
.section-head { max-width: 640px; margin-bottom: 40px; }
.section-head .eyebrow {
    font-family: 'IBM Plex Mono', monospace; font-size: .78rem; letter-spacing: 2px;
    text-transform: uppercase; color: var(--copper); display: block; margin-bottom: 10px;
}
.section-head h2 { font-size: 1.9rem; margin: 0 0 12px; }
.section-head p { color: var(--text-muted); margin: 0; }

/* ===================== STAT STRIP ===================== */
.stats { display: grid; grid-template-columns: repeat(4, 1fr); gap: 20px; }
.stat {
    background: #fff; border: 1px solid var(--border); border-radius: var(--radius);
    padding: 26px 24px; text-align: center;
}
.stat .num { font-size: 2.4rem; font-weight: 700; color: var(--silicon-900); font-family: 'IBM Plex Mono', monospace; }
.stat .num span { color: var(--copper); }
.stat .label { color: var(--text-muted); font-size: .92rem; margin-top: 4px; }

/* ===================== CARDS ===================== */
.card-grid { display: grid; gap: 22px; }
.cols-3 { grid-template-columns: repeat(3, 1fr); }
.cols-2 { grid-template-columns: repeat(2, 1fr); }

.card {
    background: #fff; border: 1px solid var(--border); border-radius: var(--radius);
    overflow: hidden; display: flex; flex-direction: column; transition: transform .18s, box-shadow .18s;
}
.card:hover { transform: translateY(-3px); box-shadow: var(--shadow-md); }
.card-body { padding: 22px 22px 24px; display: flex; flex-direction: column; flex: 1; }
.card h3 { font-size: 1.12rem; margin: 0 0 8px; }
.card p { color: var(--text-muted); font-size: .93rem; margin: 0 0 16px; }
.card .card-foot { margin-top: auto; }

.tag {
    display: inline-block; font-size: .72rem; font-weight: 600; letter-spacing: .4px;
    padding: 3px 10px; border-radius: 999px; text-transform: uppercase;
}
.tag-copper { background: rgba(176,111,60,.12); color: var(--copper); }
.tag-amber  { background: var(--amber-soft); color: #8a6100; }
.tag-teal   { background: rgba(23,135,158,.12); color: var(--teal); }
.tag-gray   { background: var(--silicon-100); color: var(--silicon-700); }

.tech-chips { display: flex; flex-wrap: wrap; gap: 6px; margin-top: 4px; }
.chip {
    font-family: 'IBM Plex Mono', monospace; font-size: .72rem;
    background: var(--silicon-100); color: var(--silicon-700);
    padding: 3px 8px; border-radius: 6px;
}

/* ===================== RESEARCH DIRECTION CARD ===================== */
.dir-card .dir-index {
    font-family: 'IBM Plex Mono', monospace; font-size: .8rem; color: var(--copper);
    border-bottom: 2px solid var(--amber); display: inline-block; padding-bottom: 2px; margin-bottom: 14px;
}

/* ===================== PEOPLE ===================== */
.person-card { text-align: center; padding: 28px 20px; }
.avatar {
    width: 96px; height: 96px; border-radius: 50%; margin: 0 auto 16px;
    background: linear-gradient(135deg, var(--silicon-700), var(--silicon-500));
    color: #fff; display: flex; align-items: center; justify-content: center;
    font-size: 1.9rem; font-weight: 700; font-family: 'IBM Plex Mono', monospace;
    border: 3px solid var(--amber-soft);
}
.person-card h3 { margin: 0 0 2px; font-size: 1.05rem; }
.person-role { color: var(--copper); font-size: .88rem; font-weight: 600; }
.person-dept { color: var(--text-muted); font-size: .82rem; }

/* ===================== FILTER BAR ===================== */
.filter-bar {
    display: flex; flex-wrap: wrap; gap: 12px; align-items: flex-end;
    background: #fff; border: 1px solid var(--border); border-radius: var(--radius);
    padding: 18px 20px; margin-bottom: 30px;
}
.filter-bar .field { display: flex; flex-direction: column; gap: 6px; }
.filter-bar label { font-size: .8rem; font-weight: 600; color: var(--silicon-700); }
.filter-bar select, .filter-bar input[type=text] {
    padding: 9px 12px; border: 1px solid var(--border); border-radius: 8px;
    font-family: inherit; font-size: .92rem; min-width: 200px; background: #fff;
}
.filter-bar select:focus, .filter-bar input:focus { outline: 2px solid var(--amber); border-color: var(--amber); }

/* ===================== PROJECT LIST ===================== */
.project-card { padding: 24px; }
.project-card .proj-top { display: flex; justify-content: space-between; align-items: flex-start; gap: 12px; margin-bottom: 10px; }
.proj-maso { font-family: 'IBM Plex Mono', monospace; font-size: .78rem; color: var(--text-muted); }
.proj-meta { display: flex; flex-wrap: wrap; gap: 18px; margin-top: 14px; font-size: .85rem; color: var(--text-muted); }
.proj-meta b { color: var(--silicon-900); font-weight: 600; }

/* Trạng thái dự án */
.status { font-size: .74rem; font-weight: 600; padding: 4px 11px; border-radius: 999px; white-space: nowrap; }
.status.dang    { background: rgba(23,135,158,.12); color: var(--teal); }
.status.nghiem  { background: rgba(46,160,67,.14); color: #2e7d32; }
.status.dexuat  { background: var(--amber-soft); color: #8a6100; }
.status.tamdung { background: var(--silicon-100); color: var(--silicon-500); }

/* ===================== DETAIL PAGES ===================== */
.page-hero {
    background: var(--silicon-900); color: #fff; padding: 54px 0;
    position: relative; overflow: hidden;
}
.page-hero:after {
    content: ''; position: absolute; inset: 0; opacity: .12;
    background-image: linear-gradient(90deg, var(--amber) 1px, transparent 1px);
    background-size: 30px 30px;
    -webkit-mask-image: linear-gradient(90deg, transparent, #000);
    mask-image: linear-gradient(90deg, transparent, #000);
}
.page-hero .container { position: relative; z-index: 1; }
.page-hero .eyebrow { font-family: 'IBM Plex Mono', monospace; color: var(--amber); letter-spacing: 2px; text-transform: uppercase; font-size: .78rem; }
.page-hero h1 { color: #fff; margin: 10px 0 0; font-size: 2.1rem; }
.breadcrumb { font-size: .85rem; color: var(--silicon-300); margin-bottom: 10px; }
.breadcrumb a { color: var(--silicon-300); }
.breadcrumb a:hover { color: var(--amber); }

.detail-layout { display: grid; grid-template-columns: 1fr 320px; gap: 40px; }
.prose { font-size: 1.02rem; color: var(--silicon-800); }
.prose p { margin: 0 0 18px; }
.sidebar-box { background: var(--silicon-50); border: 1px solid var(--border); border-radius: var(--radius); padding: 22px; margin-bottom: 22px; }
.sidebar-box h4 { margin: 0 0 14px; font-size: 1rem; }
.info-row { display: flex; justify-content: space-between; gap: 12px; padding: 8px 0; border-bottom: 1px dashed var(--border); font-size: .9rem; }
.info-row:last-child { border-bottom: 0; }
.info-row .k { color: var(--text-muted); }
.info-row .v { font-weight: 600; text-align: right; }

.member-list { list-style: none; padding: 0; margin: 0; }
.member-list li { display: flex; justify-content: space-between; gap: 10px; padding: 10px 0; border-bottom: 1px solid var(--border); font-size: .9rem; }
.member-list li:last-child { border-bottom: 0; }
.member-list .role { color: var(--copper); font-size: .8rem; }

/* ===================== NEWS ===================== */
.news-card .news-date { font-family: 'IBM Plex Mono', monospace; font-size: .78rem; color: var(--copper); }
.news-thumb { height: 8px; background: linear-gradient(90deg, var(--copper), var(--amber)); }

/* ===================== CONTACT FORM ===================== */
.form-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 18px; }
.form-field { display: flex; flex-direction: column; gap: 6px; }
.form-field.full { grid-column: 1 / -1; }
.form-field label { font-weight: 600; font-size: .9rem; color: var(--silicon-700); }
.form-field input, .form-field textarea {
    padding: 11px 14px; border: 1px solid var(--border); border-radius: 8px;
    font-family: inherit; font-size: .95rem; width: 100%;
}
.form-field input:focus, .form-field textarea:focus { outline: 2px solid var(--amber); border-color: var(--amber); }
.form-field textarea { min-height: 140px; resize: vertical; }
.field-error, .text-danger { color: #c0392b; font-size: .82rem; }
.validation-summary-errors ul { margin: 0; padding-left: 18px; color: #c0392b; font-size: .88rem; }
.alert-success {
    background: #e7f6ec; border: 1px solid #b7e0c4; color: #1e6b34;
    padding: 14px 18px; border-radius: 8px; margin-bottom: 22px;
}

/* ===================== EMPTY / MISC ===================== */
.empty { text-align: center; padding: 60px 20px; color: var(--text-muted); }
.divider { height: 1px; background: var(--border); border: 0; margin: 40px 0; }
.center { text-align: center; }
.mt-32 { margin-top: 32px; }

/* ===================== FOOTER ===================== */
.site-footer { background: var(--silicon-900); color: var(--silicon-300); margin-top: 40px; }
.footer-grid { display: grid; grid-template-columns: 1.5fr 1fr 1fr; gap: 40px; padding: 56px 0 40px; }
.footer-brand { color: #fff; font-weight: 700; font-size: 1.1rem; margin-bottom: 8px; }
.site-footer p { margin: 4px 0; font-size: .9rem; }
.site-footer h4 { color: #fff; font-size: .95rem; margin: 0 0 14px; }
.site-footer a { display: block; color: var(--silicon-300); font-size: .9rem; padding: 4px 0; }
.site-footer a:hover { color: var(--amber); }
.footer-bottom { border-top: 1px solid var(--silicon-700); padding: 20px 0; font-size: .85rem; }

.sp-thumb {
    width: 100%;
    height: 210px;
    object-fit: cover;
    background: #eef2f7;
    display: block;
}
.sp-thumb {
    width: 100%;
    height: 210px;
    object-fit: cover;
    background: #eef2f7;
    display: block;
}

.sp-gallery {
    display: flex;
    flex-direction: column;
    gap: 16px;
    margin: 0 0 22px;
}

    .sp-gallery img {
        max-width: 100%;
        height: auto;
        border-radius: 10px;
        display: block;
    }

.sp-status {
    font-size: .74rem;
    font-weight: 600;
    padding: 4px 11px;
    border-radius: 999px;
}

    .sp-status.tmh {
        background: rgba(46,160,67,.14);
        color: #2e7d32;
    }
    /* Thương mại hóa */
    .sp-status.dpt {
        background: rgba(23,135,158,.12);
        color: #17879e;
    }
    /* Đang phát triển */
    .sp-status.npm {
        background: #ffe9b8;
        color: #8a6100;
    }
    /* Nguyên mẫu */
    .sp-status.nsx {
        background: #eef2f7;
        color: #55677d;
    }
/* Ngừng sản xuất */
.sp-gallery {
    display: flex;
    flex-direction: column;
    gap: 16px;
    margin: 0 0 22px;
}

    .sp-gallery img {
        max-width: 100%;
        height: auto;
        border-radius: 10px;
        display: block;
    }

.sp-status {
    font-size: .74rem;
    font-weight: 600;
    padding: 4px 11px;
    border-radius: 999px;
}

    .sp-status.tmh {
        background: rgba(46,160,67,.14);
        color: #2e7d32;
    }
    /* Thương mại hóa */
    .sp-status.dpt {
        background: rgba(23,135,158,.12);
        color: #17879e;
    }
    /* Đang phát triển */
    .sp-status.npm {
        background: #ffe9b8;
        color: #8a6100;
    }
    /* Nguyên mẫu */
    .sp-status.nsx {
        background: #eef2f7;
        color: #55677d;
    }
/* Ngừng sản xuất */

/* ===================== RESPONSIVE ===================== */
@media (max-width: 900px) {
    .hero .container { grid-template-columns: 1fr; }
    .wafer { max-width: 260px; }
    .cols-3, .stats { grid-template-columns: repeat(2, 1fr); }
    .detail-layout { grid-template-columns: 1fr; }
    .footer-grid { grid-template-columns: 1fr; gap: 28px; }
}
@media (max-width: 680px) {
    .nav-toggle { display: flex; }
    .main-nav {
        display: none; position: absolute; top: 72px; left: 0; right: 0;
        background: #fff; border-bottom: 1px solid var(--border);
        flex-direction: column; align-items: stretch; padding: 12px 24px 20px;
    }
    .main-nav.open { display: flex; }
    .cols-2, .cols-3, .stats, .form-grid { grid-template-columns: 1fr; }
    .hero h1 { font-size: 2rem; }
}

@media (prefers-reduced-motion: reduce) {
    * { animation: none !important; transition: none !important; }
}