/* ============================================================
   柯德瑋 Te-Wei Ko — Portfolio Design System
   Dark editorial theme · Magazine-grade typography · Minimalist
   ============================================================ */

/* --- CSS Custom Properties --- */
:root {
    --bg-base: #060608;
    --bg-surface: #0b0b10;
    --bg-card: #111118;
    --bg-card-hover: #16161f;
    --bg-elevated: #1a1a24;

    --border-subtle: rgba(255, 255, 255, 0.05);
    --border-default: rgba(255, 255, 255, 0.08);
    --border-active: rgba(255, 255, 255, 0.14);

    --text-primary: #e6e6ed;
    --text-secondary: #9a9aa6;
    --text-tertiary: #64646e;
    --text-muted: #484850;

    --accent: #00d4aa;
    --accent-dim: rgba(0, 212, 170, 0.12);
    --accent-glow: rgba(0, 212, 170, 0.25);
    --accent-2: #8b9cf7;
    --accent-2-dim: rgba(139, 156, 247, 0.1);
    --accent-amber: #e8a850;

    --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    --font-tc: 'Noto Sans TC', sans-serif;
    --font-mono: 'JetBrains Mono', 'SF Mono', 'Fira Code', monospace;

    --max-width: 960px;
    --nav-h: 56px;

    --radius-sm: 6px;
    --radius-md: 10px;
    --radius-lg: 16px;
    --radius-xl: 24px;

    --ease-out: cubic-bezier(0.16, 1, 0.3, 1);
    --ease-in-out: cubic-bezier(0.65, 0, 0.35, 1);
}

/* --- Reset --- */
*, *::before, *::after { margin: 0; padding: 0; box-sizing: border-box; }

html {
    scroll-behavior: smooth;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
    text-rendering: optimizeLegibility;
    font-size: 16px;
}

body {
    font-family: var(--font-sans);
    background: var(--bg-base);
    color: var(--text-primary);
    line-height: 1.75;
    overflow-x: hidden;
}

::selection { background: var(--accent-dim); color: var(--accent); }

img { display: block; max-width: 100%; }
a { color: inherit; text-decoration: none; }

/* --- Container --- */
.container {
    width: 100%;
    max-width: var(--max-width);
    margin: 0 auto;
    padding: 0 24px;
}

/* ============================================================
   NAVIGATION
   ============================================================ */
.nav {
    position: fixed;
    top: 0; left: 0; right: 0;
    height: var(--nav-h);
    z-index: 100;
    transition: background 0.3s var(--ease-out), box-shadow 0.3s var(--ease-out);
}
.nav.scrolled {
    background: rgba(6, 6, 8, 0.85);
    -webkit-backdrop-filter: blur(16px) saturate(180%);
    backdrop-filter: blur(16px) saturate(180%);
    box-shadow: 0 1px 0 var(--border-subtle);
}

.nav-inner {
    max-width: var(--max-width);
    margin: 0 auto;
    padding: 0 24px;
    height: 100%;
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.nav-logo {
    font-family: var(--font-mono);
    font-size: 1.05rem;
    font-weight: 500;
    letter-spacing: 0.04em;
    color: var(--text-primary);
    transition: color 0.2s;
}
.nav-logo:hover { color: var(--accent); }

.nav-links {
    display: flex;
    gap: 32px;
    list-style: none;
}
.nav-link {
    font-size: 0.875rem;
    font-weight: 400;
    color: var(--text-secondary);
    letter-spacing: 0.01em;
    transition: color 0.2s;
    position: relative;
}
.nav-link:hover, .nav-link.active { color: var(--text-primary); }
.nav-link.active::after {
    content: '';
    position: absolute;
    bottom: -4px; left: 0; right: 0;
    height: 1.5px;
    background: var(--accent);
    border-radius: 1px;
}

.nav-toggle {
    display: none;
    flex-direction: column;
    gap: 5px;
    background: none;
    border: none;
    cursor: pointer;
    padding: 4px;
}
.nav-toggle span {
    display: block;
    width: 20px;
    height: 1.5px;
    background: var(--text-primary);
    border-radius: 1px;
    transition: transform 0.3s var(--ease-out), opacity 0.2s;
}
.nav-toggle.active span:first-child { transform: translateY(3.25px) rotate(45deg); }
.nav-toggle.active span:last-child { transform: translateY(-3.25px) rotate(-45deg); }

/* ============================================================
   HERO
   ============================================================ */
.hero {
    position: relative;
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 120px 24px 80px;
    overflow: hidden;
}

.hero-bg {
    position: absolute;
    inset: 0;
    background:
        radial-gradient(ellipse 70% 50% at 50% 0%, rgba(0, 212, 170, 0.06) 0%, transparent 55%),
        radial-gradient(ellipse 50% 40% at 80% 60%, rgba(139, 156, 247, 0.04) 0%, transparent 55%),
        radial-gradient(ellipse 40% 30% at 20% 80%, rgba(232, 168, 80, 0.03) 0%, transparent 55%);
    pointer-events: none;
}

.hero-content {
    position: relative;
    text-align: center;
    max-width: 780px;
}

/* Avatar */
.hero-avatar-wrap {
    position: relative;
    display: inline-block;
    margin-bottom: 36px;
}
.hero-avatar-glow {
    position: absolute;
    inset: -12px;
    border-radius: 50%;
    background: radial-gradient(circle, var(--accent-dim) 0%, transparent 70%);
    animation: avatarPulse 4s ease-in-out infinite;
}
@keyframes avatarPulse {
    0%, 100% { opacity: 0.6; transform: scale(1); }
    50% { opacity: 1; transform: scale(1.04); }
}
.hero-avatar {
    position: relative;
    width: 96px;
    height: 96px;
    border-radius: 50%;
    border: 2px solid var(--border-default);
    object-fit: cover;
}

/* Name */
.hero-name {
    font-family: var(--font-tc);
    font-size: clamp(2.5rem, 6vw, 4rem);
    font-weight: 900;
    letter-spacing: 0.04em;
    line-height: 1.15;
    margin-bottom: 8px;
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 4px;
}
.hero-name-en {
    font-family: var(--font-sans);
    font-size: 0.35em;
    font-weight: 300;
    letter-spacing: 0.08em;
    color: var(--text-secondary);
    text-transform: uppercase;
}

/* Tagline */
.hero-tagline-wrap {
    margin: 40px 0 32px;
}
.hero-tagline {
    font-family: var(--font-tc);
    font-size: clamp(1.25rem, 3vw, 1.75rem);
    font-weight: 500;
    line-height: 1.55;
    color: var(--text-primary);
    letter-spacing: 0.03em;
    margin-bottom: 16px;
}
.hero-tagline-accent {
    color: var(--accent);
    font-weight: 700;
}
.hero-tagline-en {
    font-family: var(--font-sans);
    font-size: clamp(1rem, 2.2vw, 1.2rem);
    font-weight: 300;
    font-style: italic;
    color: var(--text-secondary);
    letter-spacing: 0.02em;
    line-height: 1.4;
}
.hero-tagline-accent-en {
    color: var(--accent);
    font-style: normal;
    font-weight: 500;
}

/* Bio */
.hero-bio {
    font-size: 0.95rem;
    color: var(--text-tertiary);
    line-height: 1.7;
    margin-bottom: 36px;
}

/* CTA Links */
.hero-cta {
    display: flex;
    justify-content: center;
    gap: 20px;
    flex-wrap: wrap;
}
.hero-link {
    display: inline-flex;
    align-items: center;
    gap: 7px;
    padding: 9px 20px;
    border-radius: var(--radius-xl);
    font-size: 0.85rem;
    font-weight: 500;
    letter-spacing: 0.01em;
    background: var(--bg-card);
    border: 1px solid var(--border-default);
    color: var(--text-secondary);
    transition: all 0.25s var(--ease-out);
}
.hero-link svg { width: 16px; height: 16px; }
.hero-link:hover {
    color: var(--text-primary);
    border-color: var(--border-active);
    background: var(--bg-card-hover);
    transform: translateY(-1px);
}

/* Scroll indicator */
.hero-scroll {
    position: absolute;
    bottom: 32px;
    left: 50%;
    transform: translateX(-50%);
    animation: bounce 2s ease-in-out infinite;
}
.hero-scroll span {
    display: block;
    width: 20px;
    height: 20px;
    border-right: 1.5px solid var(--text-tertiary);
    border-bottom: 1.5px solid var(--text-tertiary);
    transform: rotate(45deg);
    opacity: 0.5;
}
@keyframes bounce {
    0%, 100% { transform: translateX(-50%) translateY(0); }
    50% { transform: translateX(-50%) translateY(8px); }
}

/* ============================================================
   SECTIONS (shared)
   ============================================================ */
.section {
    padding: 120px 0;
}

.section-label {
    font-family: var(--font-mono);
    font-size: 0.75rem;
    font-weight: 500;
    letter-spacing: 0.12em;
    text-transform: uppercase;
    color: var(--accent);
    margin-bottom: 12px;
}

.section-title {
    font-family: var(--font-tc);
    font-size: clamp(1.75rem, 4vw, 2.5rem);
    font-weight: 700;
    letter-spacing: 0.02em;
    line-height: 1.25;
    margin-bottom: 16px;
}

.section-desc {
    font-size: 1rem;
    color: var(--text-secondary);
    line-height: 1.7;
    max-width: 640px;
    margin-bottom: 64px;
}

/* ============================================================
   RESEARCH
   ============================================================ */
.research-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 24px;
    margin-bottom: 80px;
}

.research-card {
    background: var(--bg-card);
    border: 1px solid var(--border-subtle);
    border-radius: var(--radius-lg);
    padding: 36px 28px;
    transition: all 0.35s var(--ease-out);
    position: relative;
    overflow: hidden;
}
.research-card::before {
    content: '';
    position: absolute;
    top: 0; left: 0; right: 0;
    height: 1px;
    background: linear-gradient(90deg, transparent, var(--accent-dim), transparent);
    opacity: 0;
    transition: opacity 0.35s var(--ease-out);
}
.research-card:hover {
    border-color: var(--border-active);
    background: var(--bg-card-hover);
    transform: translateY(-2px);
}
.research-card:hover::before { opacity: 1; }

.research-card-icon {
    width: 44px;
    height: 44px;
    border-radius: var(--radius-md);
    background: var(--accent-dim);
    display: flex;
    align-items: center;
    justify-content: center;
    margin-bottom: 20px;
}
.research-card-icon svg {
    width: 22px;
    height: 22px;
    color: var(--accent);
}

.research-card h3 {
    font-family: var(--font-tc);
    font-size: 1.15rem;
    font-weight: 700;
    letter-spacing: 0.03em;
    margin-bottom: 2px;
}
.research-card > p {
    font-size: 0.8rem;
    color: var(--text-tertiary);
    letter-spacing: 0.03em;
    margin-bottom: 16px;
}
.research-card-detail {
    font-size: 0.875rem;
    color: var(--text-secondary);
    line-height: 1.7;
}

/* --- H.O.L.O. Mission --- */
.holo-mission {
    position: relative;
    max-width: 720px;
    margin: 0 auto;
    text-align: center;
    padding: 48px 0 0;
}
.holo-line {
    width: 40px;
    height: 2px;
    background: var(--accent);
    margin: 0 auto 28px;
    border-radius: 1px;
}
.holo-label {
    font-family: var(--font-mono);
    font-size: 0.75rem;
    font-weight: 500;
    letter-spacing: 0.14em;
    color: var(--accent);
    text-transform: uppercase;
    margin-bottom: 24px;
}
.holo-quote {
    font-family: var(--font-tc);
    font-size: 1.05rem;
    font-weight: 500;
    color: var(--text-primary);
    line-height: 1.8;
    letter-spacing: 0.02em;
    margin-bottom: 28px;
    font-style: italic;
}
.holo-desc {
    font-size: 0.925rem;
    color: var(--text-secondary);
    line-height: 1.8;
}

/* ============================================================
   PROJECTS — Featured Cards
   ============================================================ */
.project-featured {
    position: relative;
    background: var(--bg-card);
    border: 1px solid var(--border-subtle);
    border-radius: var(--radius-xl);
    padding: 44px 40px;
    margin-bottom: 28px;
    transition: all 0.35s var(--ease-out);
    overflow: hidden;
}
.project-featured:last-of-type { margin-bottom: 64px; }

.project-featured-bg {
    position: absolute;
    inset: 0;
    background: radial-gradient(ellipse 80% 80% at 100% 0%, var(--accent-dim), transparent 60%);
    opacity: 0;
    transition: opacity 0.5s var(--ease-out);
    pointer-events: none;
}
.project-featured:hover { border-color: var(--border-active); transform: translateY(-1px); }
.project-featured:hover .project-featured-bg { opacity: 0.5; }

.project-featured-content { position: relative; }

.project-featured-meta {
    display: flex;
    align-items: center;
    gap: 12px;
    margin-bottom: 16px;
}
.project-featured-badge {
    font-family: var(--font-mono);
    font-size: 0.7rem;
    font-weight: 500;
    letter-spacing: 0.08em;
    text-transform: uppercase;
    color: var(--accent);
    background: var(--accent-dim);
    padding: 3px 10px;
    border-radius: var(--radius-sm);
}
.project-featured-lang {
    font-size: 0.75rem;
    color: var(--text-tertiary);
    letter-spacing: 0.03em;
}

.project-featured-title {
    font-family: var(--font-mono);
    font-size: 1.75rem;
    font-weight: 500;
    letter-spacing: -0.02em;
    margin-bottom: 6px;
}
.project-featured-subtitle {
    font-family: var(--font-tc);
    font-size: 1rem;
    color: var(--text-secondary);
    margin-bottom: 20px;
    letter-spacing: 0.02em;
}
.project-featured-desc {
    font-size: 0.9rem;
    color: var(--text-secondary);
    line-height: 1.75;
    max-width: 680px;
    margin-bottom: 24px;
}

/* Stats */
.project-featured-stats {
    display: flex;
    gap: 32px;
    margin-bottom: 24px;
    padding: 16px 20px;
    background: rgba(255, 255, 255, 0.015);
    border-radius: var(--radius-md);
    border: 1px solid var(--border-subtle);
}
.project-stat { text-align: center; flex: 1; }
.project-stat-value {
    display: block;
    font-family: var(--font-mono);
    font-size: 1.05rem;
    font-weight: 500;
    color: var(--accent);
    margin-bottom: 2px;
}
.project-stat-label {
    font-size: 0.72rem;
    color: var(--text-tertiary);
    letter-spacing: 0.02em;
}

/* Tags */
.project-featured-tags {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
    margin-bottom: 24px;
}
.project-featured-tags span {
    font-size: 0.72rem;
    color: var(--text-tertiary);
    background: rgba(255, 255, 255, 0.03);
    padding: 4px 10px;
    border-radius: var(--radius-sm);
    border: 1px solid var(--border-subtle);
    letter-spacing: 0.02em;
}

.project-featured-link {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    font-family: var(--font-mono);
    font-size: 0.8rem;
    font-weight: 500;
    color: var(--accent);
    letter-spacing: 0.03em;
    transition: gap 0.25s var(--ease-out);
}
.project-featured-link:hover { gap: 10px; }

/* ============================================================
   PROJECTS — Mini Grid
   ============================================================ */
.projects-mini { padding-top: 16px; }

.projects-mini-title {
    font-family: var(--font-tc);
    font-size: 1.1rem;
    font-weight: 600;
    margin-bottom: 24px;
    letter-spacing: 0.02em;
}

.projects-mini-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 16px;
}

.project-mini-card {
    display: flex;
    align-items: flex-start;
    gap: 14px;
    padding: 18px 20px;
    background: var(--bg-card);
    border: 1px solid var(--border-subtle);
    border-radius: var(--radius-md);
    transition: all 0.25s var(--ease-out);
}
.project-mini-card:hover {
    border-color: var(--border-active);
    background: var(--bg-card-hover);
    transform: translateY(-1px);
}

.project-mini-icon {
    font-family: var(--font-mono);
    font-size: 1.3rem;
    color: var(--accent);
    line-height: 1;
    flex-shrink: 0;
    width: 28px;
    text-align: center;
}

.project-mini-card h4 {
    font-family: var(--font-mono);
    font-size: 0.85rem;
    font-weight: 500;
    margin-bottom: 3px;
}
.project-mini-card p {
    font-size: 0.75rem;
    color: var(--text-tertiary);
    line-height: 1.4;
}

/* ============================================================
   CONTACT
   ============================================================ */
.contact-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 20px;
}

.contact-card {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 10px;
    padding: 36px 24px;
    background: var(--bg-card);
    border: 1px solid var(--border-subtle);
    border-radius: var(--radius-lg);
    text-align: center;
    transition: all 0.3s var(--ease-out);
}
.contact-card:hover {
    border-color: var(--border-active);
    background: var(--bg-card-hover);
    transform: translateY(-2px);
}

.contact-card-icon {
    width: 48px;
    height: 48px;
    border-radius: 50%;
    background: var(--accent-dim);
    display: flex;
    align-items: center;
    justify-content: center;
    margin-bottom: 4px;
}
.contact-card-icon svg {
    width: 22px;
    height: 22px;
    color: var(--accent);
}

.contact-card-label {
    font-family: var(--font-mono);
    font-size: 0.72rem;
    font-weight: 500;
    letter-spacing: 0.08em;
    text-transform: uppercase;
    color: var(--text-tertiary);
}
.contact-card-value {
    font-size: 0.875rem;
    color: var(--text-secondary);
    word-break: break-all;
}

/* ============================================================
   FOOTER
   ============================================================ */
.footer {
    padding: 48px 0;
    border-top: 1px solid var(--border-subtle);
    text-align: center;
}
.footer p {
    font-size: 0.8rem;
    color: var(--text-muted);
    letter-spacing: 0.02em;
}
.footer-tagline {
    margin-top: 6px;
    font-size: 0.75rem !important;
    color: var(--text-tertiary) !important;
}

/* ============================================================
   REVEAL ANIMATIONS
   ============================================================ */
.reveal {
    opacity: 0;
    transform: translateY(28px);
    transition: opacity 0.7s var(--ease-out), transform 0.7s var(--ease-out);
}
.reveal.visible {
    opacity: 1;
    transform: translateY(0);
}

/* Stagger children */
.research-grid .reveal:nth-child(1) { transition-delay: 0s; }
.research-grid .reveal:nth-child(2) { transition-delay: 0.08s; }
.research-grid .reveal:nth-child(3) { transition-delay: 0.16s; }

/* ============================================================
   RESPONSIVE
   ============================================================ */

/* Tablet */
@media (max-width: 768px) {
    .section { padding: 80px 0; }

    .nav-links {
        position: fixed;
        top: var(--nav-h);
        left: 0; right: 0;
        background: rgba(6, 6, 8, 0.95);
        -webkit-backdrop-filter: blur(20px);
        backdrop-filter: blur(20px);
        flex-direction: column;
        align-items: center;
        gap: 0;
        padding: 16px 0;
        border-bottom: 1px solid var(--border-subtle);
        transform: translateY(-100%);
        opacity: 0;
        pointer-events: none;
        transition: all 0.3s var(--ease-out);
    }
    .nav-links.open {
        transform: translateY(0);
        opacity: 1;
        pointer-events: auto;
    }
    .nav-link {
        display: block;
        padding: 14px 24px;
        font-size: 0.9rem;
    }
    .nav-toggle { display: flex; }

    .research-grid { grid-template-columns: 1fr; gap: 16px; }
    .project-featured { padding: 28px 24px; }
    .project-featured-stats { flex-direction: column; gap: 12px; }
    .projects-mini-grid { grid-template-columns: 1fr; }
    .contact-grid { grid-template-columns: 1fr; }
}

/* Small phone */
@media (max-width: 480px) {
    .hero { padding: 100px 16px 60px; }
    .hero-avatar { width: 72px; height: 72px; }
    .project-featured-title { font-size: 1.35rem; }
}