:root[data-theme="dark"] {
    --bg: #030712;
    --bg2: #0d1321;
    --card: #0f1e2e;
    --card2: #162032;
    --text: #e8f0fe;
    --muted: #7a92b2;
    --accent: #38bdf8;
    --accent2: #818cf8;
    --accent3: #34d399;
    --glow: rgba(56,189,248,0.12);
    --glow2: rgba(129,140,248,0.12);
    --border: rgba(56,189,248,0.15);
    --border2: rgba(255,255,255,0.07);
    --shadow: 0 8px 32px rgba(0,0,0,0.4);
    --nav-bg: rgba(3,7,18,0.92);
    --brand-text: #807ffe;
}
:root[data-theme="light"] {
    --bg: #f0f6ff;
    --bg2: #e4eeff;
    --card: #ffffff;
    --card2: #f8fbff;
    --text: #0d1b2e;
    --muted: #4a6080;
    --accent: #0284c7;
    --accent2: #4f46e5;
    --accent3: #059669;
    --glow: rgba(2,132,199,0.08);
    --glow2: rgba(79,70,229,0.08);
    --border: rgba(2,132,199,0.2);
    --border2: rgba(0,0,0,0.06);
    --shadow: 0 8px 32px rgba(0,0,0,0.08);
    --nav-bg: rgba(240,246,255,0.94);
    --brand-text: #807ffe;
}

* { box-sizing: border-box; margin: 0; padding: 0; }

/* 強制遵守 hidden（避免被 display 規則覆蓋） */
[hidden] { display: none !important; }

html { scroll-behavior: smooth; }

body {
    font-family: 'Noto Sans TC', 'DM Mono', sans-serif;
    background: var(--bg);
    color: var(--text);
    line-height: 1.75;
    transition: background 0.3s, color 0.3s;
}

.container { max-width: 1100px; margin: 0 auto; padding: 0 28px; }

/* ── NAV ── */
nav {
    position: fixed; top: 0; width: 100%;
    background: var(--nav-bg);
    backdrop-filter: blur(16px) saturate(180%);
    border-bottom: 1px solid var(--border2);
    z-index: 1000;
    padding: 12px 0;
}
.nav-inner { display: flex; justify-content: space-between; align-items: center; padding-bottom: 6px; }
.nav-brand {
    display: flex;
    align-items: flex-end;
    gap: 1px;
    font-family: 'Syne', sans-serif;
    font-weight: 800;
    font-size: 1.1rem;
    color: var(--accent);
    letter-spacing: 0.05em;
}
.brand-icon {
    height: 36px;
    width: auto;
    object-fit: contain;
    flex: 0 0 auto;
}
.brand-text {
    color: var(--brand-text);
    font-size: 1.4rem;
    line-height: 0.95;
    transform: translateY(2px);
}
.nav-controls { display: flex; gap: 10px; }
.btn-menu { display: none; }
.btn-toggle {
    background: var(--card);
    border: 1px solid var(--border2);
    color: var(--text);
    padding: 7px 14px;
    border-radius: 8px;
    cursor: pointer;
    font-size: 0.82rem;
    font-weight: 600;
    letter-spacing: 0.02em;
    transition: border-color 0.2s, background 0.2s;
}
.btn-toggle:hover { border-color: var(--accent); background: var(--glow); }

/* 漢堡選單（小螢幕） */
.nav-menu {
    display: flex;
    gap: 10px;
    padding-top: 10px;
    flex-wrap: wrap;
}
.nav-menu-status {
    display: inline-flex;
    align-items: center;
    height: 34px;
    padding: 0 12px;
    border-radius: 10px;
    border: 1px solid var(--border2);
    background: var(--card2);
    color: var(--muted);
    font-size: 0.82rem;
    font-weight: 700;
    letter-spacing: 0.02em;
}

@media (max-width: 539px) {
    .nav-controls { display: none; }
    .btn-menu { display: inline-flex; }
}

/* ── SUB NAV（功能頁 TAB）── */
.subnav {
    display: flex;
    gap: 10px;
    padding: 10px 28px 2px;
    border-top: 1px solid var(--border2);
    overflow-x: auto;
}
.subnav-tab {
    display: inline-flex;
    align-items: center;
    height: 34px;
    padding: 0 12px;
    border-radius: 10px;
    border: 1px solid var(--border2);
    background: var(--card);
    color: var(--muted);
    text-decoration: none;
    font-size: 0.82rem;
    font-weight: 700;
    letter-spacing: 0.02em;
    white-space: nowrap;
    transition: border-color 0.2s, background 0.2s, color 0.2s;
}
.subnav-tab:hover { border-color: var(--accent); background: var(--glow); color: var(--text); }
.subnav-tab.is-active {
    border-color: var(--accent);
    background: var(--glow);
    color: var(--text);
}

/* ── HERO ── */
header {
    padding: 130px 0 72px;
    text-align: center;
    position: relative;
    overflow: hidden;
}
header.hero-header {
    padding-top: 10px;
}
.hero-glow {
    position: absolute;
    width: 700px; height: 700px;
    border-radius: 50%;
    background: radial-gradient(circle, rgba(56,189,248,0.07) 0%, transparent 70%);
    top: -200px; left: 50%; transform: translateX(-50%);
    pointer-events: none;
}
.hero-badge {
    display: inline-flex; align-items: center; gap: 8px;
    background: var(--glow); border: 1px solid var(--border);
    padding: 6px 16px; border-radius: 100px;
    font-size: 0.78rem; font-family: 'DM Mono', monospace;
    color: var(--accent); margin-bottom: 22px;
    letter-spacing: 0.06em;
}
h1 {
    font-family: 'Syne', sans-serif;
    font-size: clamp(2.8rem, 6vw, 4.2rem);
    font-weight: 800;
    letter-spacing: -0.02em;
    line-height: 1.1;
    margin-bottom: 18px;
}
.highlight { color: var(--accent); }
.hero-header h1 .highlight { color: var(--brand-text); }
.lead {
    font-size: 1.05rem;
    color: var(--muted);
    max-width: 680px;
    margin: 0 auto 28px;
    line-height: 1.8;
}
.contact-row {
    display: flex; justify-content: center; gap: 12px; flex-wrap: wrap;
    margin-bottom: 8px;
}
.contact-chip {
    display: inline-flex; align-items: center; gap: 7px;
    background: var(--card);
    border: 1px solid var(--border);
    padding: 8px 18px;
    border-radius: 100px;
    font-size: 0.84rem;
    font-family: 'DM Mono', monospace;
    color: var(--accent);
    font-weight: 500;
}

/* ── SECTIONS ── */
section { padding: 64px 0; }
.section-header {
    display: flex; align-items: center; gap: 16px;
    margin-bottom: 40px;
}
.section-title {
    font-family: 'Syne', sans-serif;
    font-size: 1.65rem;
    font-weight: 700;
    letter-spacing: -0.01em;
}
.section-line {
    flex: 1;
    height: 1px;
    background: linear-gradient(90deg, var(--border), transparent);
}

/* ── SKILL GRID ── */
.grid-3 { display: grid; grid-template-columns: repeat(auto-fit, minmax(300px, 1fr)); gap: 20px; }

.card {
    background: var(--card);
    padding: 28px;
    border-radius: 16px;
    border: 1px solid var(--border2);
    transition: transform 0.25s, border-color 0.25s, box-shadow 0.25s;
    position: relative; overflow: hidden;
}
.card::before {
    content: '';
    position: absolute; top: 0; left: 0; right: 0; height: 2px;
    background: linear-gradient(90deg, var(--accent), var(--accent2));
    opacity: 0;
    transition: opacity 0.25s;
}
.card:hover { transform: translateY(-4px); border-color: var(--border); box-shadow: var(--shadow); }
.card:hover::before { opacity: 1; }

.card-icon { font-size: 1.5rem; margin-bottom: 14px; }
.card h3 {
    font-family: 'Syne', sans-serif;
    font-size: 0.95rem; font-weight: 700;
    color: var(--accent);
    text-transform: uppercase;
    letter-spacing: 0.06em;
    margin-bottom: 18px;
}
.tag-wrap { display: flex; flex-wrap: wrap; gap: 7px; }
.tag {
    background: var(--bg2);
    border: 1px solid var(--border2);
    padding: 4px 11px;
    border-radius: 6px;
    font-size: 0.8rem;
    color: var(--muted);
    font-family: 'DM Mono', monospace;
    transition: border-color 0.2s, color 0.2s;
}
.tag:hover { border-color: var(--accent); color: var(--text); }
.tag.pro {
    background: var(--glow);
    border-color: rgba(56,189,248,0.35);
    color: var(--accent);
    font-weight: 500;
}
.tag.pro2 {
    background: var(--glow2);
    border-color: rgba(129,140,248,0.35);
    color: var(--accent2);
    font-weight: 500;
}
.tag.green {
    background: rgba(52,211,153,0.1);
    border-color: rgba(52,211,153,0.3);
    color: var(--accent3);
    font-weight: 500;
}

/* ── PROJECTS ── */
.project-list { display: flex; flex-direction: column; gap: 24px; }

.project-item {
    background: var(--card);
    padding: 34px;
    border-radius: 18px;
    border: 1px solid var(--border2);
    position: relative; overflow: hidden;
    transition: transform 0.25s, box-shadow 0.25s, border-color 0.25s;
}
.project-item::after {
    content: '';
    position: absolute;
    top: 0; left: 0; bottom: 0; width: 3px;
    background: linear-gradient(180deg, var(--accent), var(--accent2));
    border-radius: 2px 0 0 2px;
}
.project-item:hover { transform: translateX(4px); border-color: var(--border); box-shadow: var(--shadow); }

.project-header {
    display: flex; justify-content: space-between; align-items: flex-start;
    margin-bottom: 14px; flex-wrap: wrap; gap: 10px;
}
.project-name {
    font-family: 'Syne', sans-serif;
    font-size: 1.2rem; font-weight: 700;
    color: var(--text); line-height: 1.3;
}
.project-platform {
    font-family: 'DM Mono', monospace;
    font-size: 0.75rem;
    color: var(--accent2);
    background: var(--glow2);
    border: 1px solid rgba(129,140,248,0.2);
    padding: 4px 12px;
    border-radius: 100px;
    white-space: nowrap;
}
.project-desc {
    color: var(--muted);
    margin-bottom: 20px;
    white-space: pre-line;
    font-size: 0.93rem;
    line-height: 1.8;
}
.project-highlight {
    color: var(--text);
    font-weight: 500;
}

/* ── PERF SECTION ── */
.perf-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(280px, 1fr)); gap: 16px; margin-bottom: 28px; }
.perf-card {
    background: var(--card);
    border: 1px solid var(--border2);
    border-radius: 14px;
    padding: 22px 24px;
    position: relative; overflow: hidden;
    transition: border-color 0.2s, transform 0.2s;
}
.perf-card:hover { border-color: var(--border); transform: translateY(-3px); }
.perf-card .layer-label {
    font-family: 'DM Mono', monospace;
    font-size: 0.7rem;
    letter-spacing: 0.1em;
    color: var(--accent);
    text-transform: uppercase;
    margin-bottom: 8px;
    opacity: 0.8;
}
.perf-card h4 {
    font-family: 'Syne', sans-serif;
    font-size: 1rem;
    font-weight: 700;
    margin-bottom: 10px;
    color: var(--text);
}
.perf-card p {
    font-size: 0.85rem;
    color: var(--muted);
    line-height: 1.7;
}
.perf-accent { color: var(--accent3); font-weight: 600; }
.perf-stripe {
    position: absolute; top: 0; right: 0;
    width: 60px; height: 3px;
    background: linear-gradient(90deg, var(--accent2), var(--accent));
    border-radius: 0 14px 0 4px;
}

/* ── ARCH DIAGRAM ── */
.arch-flow {
    display: flex; align-items: center; justify-content: center;
    gap: 0; flex-wrap: wrap;
    background: var(--card);
    border: 1px solid var(--border2);
    border-radius: 16px;
    padding: 28px 24px;
    margin-top: 20px;
}
.arch-node {
    display: flex; flex-direction: column; align-items: center;
    padding: 12px 16px;
    border-radius: 10px;
    border: 1px solid var(--border2);
    background: var(--card2);
    min-width: 100px; text-align: center;
    transition: border-color 0.2s;
}
.arch-node:hover { border-color: var(--accent); }
.arch-node .node-icon { font-size: 1.4rem; margin-bottom: 5px; }
.arch-node .node-label {
    font-family: 'DM Mono', monospace;
    font-size: 0.7rem;
    color: var(--accent);
    font-weight: 500;
}
.arch-node .node-sub {
    font-size: 0.68rem;
    color: var(--muted);
    margin-top: 2px;
}
.arch-arrow {
    font-size: 1.1rem;
    color: var(--border);
    padding: 0 4px;
    flex-shrink: 0;
}

/* ── SCENE BADGES ── */
.scene-badge {
    display: inline-flex; align-items: center; gap: 4px;
    font-size: 0.72rem; font-family: 'DM Mono', monospace;
    padding: 2px 10px; border-radius: 100px;
    margin-left: 8px; vertical-align: middle;
    font-weight: 600; letter-spacing: 0.04em;
}
.scene-badge.hq { background: var(--glow); border: 1px solid var(--border); color: var(--accent); }
.scene-badge.factory { background: rgba(251,191,36,0.1); border: 1px solid rgba(251,191,36,0.3); color: #fbbf24; }
.scene-badge.b2c { background: var(--glow2); border: 1px solid rgba(129,140,248,0.3); color: var(--accent2); }

/* ── INFRA SCALE SECTION ── */
.infra-wrapper {
    background: var(--card);
    border: 1px solid var(--border2);
    border-radius: 20px;
    overflow: hidden;
}
.infra-tier {
    display: grid;
    grid-template-columns: 180px 1fr;
    border-bottom: 1px solid var(--border2);
}
.infra-tier:last-child { border-bottom: none; }
.infra-tier-label {
    padding: 28px 24px;
    background: var(--card2);
    border-right: 1px solid var(--border2);
    display: flex; flex-direction: column;
    justify-content: center; align-items: flex-start; gap: 6px;
}
.tier-icon { font-size: 1.8rem; }
.tier-name {
    font-family: 'Syne', sans-serif;
    font-size: 0.85rem; font-weight: 700;
    color: var(--text);
}
.tier-scale {
    font-family: 'DM Mono', monospace;
    font-size: 0.75rem;
    color: var(--accent);
    background: var(--glow);
    border: 1px solid var(--border);
    padding: 2px 10px; border-radius: 100px;
}
.infra-tier-body {
    padding: 24px 28px;
    display: flex; flex-direction: column; gap: 8px;
}
.infra-tier-body h4 {
    font-family: 'Syne', sans-serif;
    font-size: 0.92rem; font-weight: 700;
    color: var(--text); margin-bottom: 4px;
}
.infra-tier-body p {
    font-size: 0.85rem; color: var(--muted); line-height: 1.7;
}
.infra-arrow-row {
    display: flex; justify-content: center; align-items: center;
    padding: 10px 0; gap: 12px;
}
.infra-arrow-line {
    flex: 1; height: 1px; max-width: 120px;
    background: linear-gradient(90deg, transparent, var(--border), transparent);
}
.infra-arrow-label {
    font-family: 'DM Mono', monospace;
    font-size: 0.7rem; color: var(--muted);
    letter-spacing: 0.06em;
}
.obs-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 14px;
    margin-top: 24px;
}
.obs-card {
    background: var(--card2);
    border: 1px solid var(--border2);
    border-radius: 12px;
    padding: 18px 20px;
    transition: border-color 0.2s;
}
.obs-card:hover { border-color: var(--border); }
.obs-card .obs-icon { font-size: 1.3rem; margin-bottom: 8px; }
.obs-card h5 {
    font-family: 'DM Mono', monospace;
    font-size: 0.8rem; font-weight: 500;
    color: var(--accent); margin-bottom: 5px;
}
.obs-card p { font-size: 0.8rem; color: var(--muted); line-height: 1.6; }

/* ── FOOTER ── */
footer {
    text-align: center;
    padding: 40px 0 48px;
    color: var(--muted);
    font-size: 0.85rem;
    border-top: 1px solid var(--border2);
}
footer strong { color: var(--accent); font-family: 'Syne', sans-serif; }

/* ── LANG SWITCH（沿用原本顯示邏輯，文字內容改由 i18n 載入）── */
.en { display: none; }
body[data-lang="en"] .zh { display: none; }
body[data-lang="en"] .en { display: inline; }
body[data-lang="en"] p.en,
body[data-lang="en"] div.en,
body[data-lang="en"] h2.en,
body[data-lang="en"] span.en { display: block; }
body[data-lang="en"] .perf-en,
body[data-lang="en"] .arch-en { display: flex; }

/* ── DIY 頁（片段注入）── */
#diySection .diy-lead {
    max-width: 900px;
    margin: 0 auto 28px;
    text-align: left;
}
#diySection .diy-kpis-card h3 { margin-bottom: 14px; }
#diySection .diy-kpi-list {
    margin: 0;
    padding-left: 1.25rem;
    color: var(--muted);
    font-size: 0.95rem;
    line-height: 1.75;
}
#diySection .diy-kpi-list li { margin-bottom: 0.45rem; }
#diySection .diy-pillars { margin-top: 9px; margin-bottom: 8px; }
#diySection .diy-values-card h3 { margin-bottom: 14px; }

/* ── DIY Gallery ── */
#diySection .diy-gallery { padding-top: 32px; }
#diySection .diy-gallery-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
    gap: 14px;
}
.diy-gallery-item {
    appearance: none;
    width: 100%;
    text-align: left;
    padding: 0;
    border: 1px solid var(--border2);
    border-radius: 14px;
    background: var(--card);
    overflow: hidden;
    cursor: pointer;
    transition: transform 0.2s, border-color 0.2s, box-shadow 0.2s;
}
.diy-gallery-item:hover { transform: translateY(-2px); border-color: var(--border); box-shadow: var(--shadow); }
.diy-gallery-item:focus-visible { outline: 2px solid var(--accent); outline-offset: 3px; }
.diy-gallery-thumb {
    width: 100%;
    aspect-ratio: 16 / 10;
    background: var(--bg2);
    background-size: cover;
    background-position: center;
}
.diy-gallery-meta { padding: 14px 16px 16px; }
.diy-gallery-title {
    font-family: 'Syne', sans-serif;
    font-size: 0.95rem;
    font-weight: 700;
    color: var(--text);
    letter-spacing: -0.01em;
    line-height: 1.25;
}
/* Gallery title is single DOM, translated via i18n */
.diy-gallery-sub {
    margin-top: 6px;
    font-family: 'DM Mono', monospace;
    font-size: 0.75rem;
    color: var(--muted);
}

.diy-lightbox {
    position: fixed;
    inset: 0;
    z-index: 2000;
}
.diy-lightbox-backdrop {
    position: absolute;
    inset: 0;
    background: rgba(0,0,0,0.62);
}
.diy-lightbox-panel {
    position: absolute;
    inset: 16px;
    max-width: 980px;
    width: min(980px, calc(100% - 32px));
    height: min(760px, calc(100vh - 32px));
    margin: auto;
    background: var(--card);
    border: 1px solid var(--border2);
    border-radius: 18px;
    box-shadow: var(--shadow);
    padding: 16px;
    max-height: calc(100vh - 32px);
    display: flex;
    flex-direction: column;
    overflow: hidden;
}
.diy-lightbox-close {
    position: absolute;
    top: 12px;
    right: 12px;
    height: 34px;
    width: 34px;
    padding: 0;
    border-radius: 10px;
    display: inline-flex;
    align-items: center;
    justify-content: center;
}
.diy-lightbox-head { padding: 10px 46px 12px 8px; }
.diy-lightbox-title {
    font-family: 'Syne', sans-serif;
    font-weight: 800;
    letter-spacing: -0.01em;
    color: var(--text);
    font-size: 1.05rem;
    line-height: 1.25;
}
.diy-lightbox-count {
    margin-top: 6px;
    font-family: 'DM Mono', monospace;
    font-size: 0.78rem;
    color: var(--muted);
}
.diy-lightbox-body { position: relative; flex: 1 1 auto; display: block; padding-bottom: 10px; }
.diy-lightbox-body > * { min-width: 0; }
.diy-lightbox-viewport {
    position: relative;
    width: 100%;
    margin: 0 auto;
    height: var(--diy-lightbox-h, min(70vh, 640px));
    display: flex;
    align-items: center;
    justify-content: center;
    overflow: hidden;
    touch-action: none;
}
.diy-lightbox-img {
    max-width: 100%;
    max-height: 100%;
    object-fit: contain;
    display: block;
    border-radius: 12px;
    background: transparent;
    border: 0;
    height: auto;
    box-sizing: border-box;
    transform-origin: center center;
    cursor: zoom-in;
    touch-action: none;
    -webkit-user-select: none;
    user-select: none;
}
.diy-lightbox-img.is-zoomed { cursor: grab; }
.diy-lightbox-img.is-dragging { cursor: grabbing; }
.diy-lightbox-nav {
    height: 46px;
    width: 46px;
    padding: 0;
    border-radius: 14px;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    font-size: 1.4rem;
    position: absolute;
    top: 50%;
    transform: translateY(-50%);
    z-index: 2;
}
.diy-lightbox-nav.prev { left: 10px; }
.diy-lightbox-nav.next { right: 10px; }
.diy-lightbox-nav { backdrop-filter: blur(10px) saturate(160%); }
@media (max-width: 640px) {
    .diy-lightbox-panel { padding: 12px; }
    .diy-lightbox-body { grid-template-columns: 36px 1fr 36px; }
    .diy-lightbox-nav { height: 40px; width: 40px; border-radius: 12px; }
}

/* ── RESPONSIVE ── */
@media (max-width: 640px) {
    h1 { font-size: 2.4rem; }
    .project-item { padding: 24px 20px; }
    .perf-grid { grid-template-columns: 1fr; }
    .infra-tier { grid-template-columns: 1fr; }
    .infra-tier-label { border-right: none; border-bottom: 1px solid var(--border2); flex-direction: row; align-items: center; gap: 12px; }
}