/* ═══════════════════════════════════════════════════════════════
   VARIABLES
═══════════════════════════════════════════════════════════════ */
:root {
    /* Brand */
    --accent:       #4f8ef7;
    --accent-dark:  #3570d4;
    --accent-glow:  rgba(79, 142, 247, 0.25);

    /* Light-mode surfaces */
    --navy:         #0d1b2a;
    --navy-mid:     #122035;
    --bg:           #ffffff;
    --bg-alt:       #f1f5f9;
    --bg-card:      #ffffff;

    /* Light-mode text */
    --text:         #1e293b;
    --text-muted:   #64748b;
    --text-light:   #94a3b8;

    /* Light-mode borders / shadows */
    --border:       #e2e8f0;
    --shadow:       0 2px 16px rgba(0, 0, 0, 0.07);
    --shadow-lg:    0 8px 40px rgba(0, 0, 0, 0.12);

    /* Typography */
    --font:         'Inter', system-ui, -apple-system, sans-serif;
    --serif:        'Playfair Display', Georgia, 'Times New Roman', serif;

    /* Layout */
    --radius:       12px;
    --radius-sm:    8px;
}

/* ── Dark mode overrides ─────────────────────────────────────── */
[data-theme="dark"] {
    --bg:           #0d1117;
    --bg-alt:       #161b27;
    --bg-card:      #1a2030;
    --text:         #e2e8f0;
    --text-muted:   #94a3b8;
    --text-light:   #64748b;
    --border:       rgba(255, 255, 255, 0.09);
    --shadow:       0 2px 16px rgba(0, 0, 0, 0.3);
    --shadow-lg:    0 8px 40px rgba(0, 0, 0, 0.4);
}

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

html { scroll-behavior: smooth; font-size: 16px; }

body {
    font-family: var(--font);
    color: var(--text);
    background: var(--bg);
    line-height: 1.6;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
    transition: background 0.3s, color 0.3s;
}

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

/* ═══════════════════════════════════════════════════════════════
   LAYOUT
═══════════════════════════════════════════════════════════════ */
.container { max-width: 1080px; margin: 0 auto; padding: 0 2rem; }
section    { padding: 108px 0; }

.section-dark {
    background: var(--navy);
    color: #ffffff;
}
.section-alt {
    background: var(--bg-alt);
    transition: background 0.3s;
}

.section-header { margin-bottom: 4rem; }
.section-header h2 {
    font-family: var(--serif);
    font-size: clamp(2rem, 4vw, 3rem);
    font-weight: 700;
    line-height: 1.15;
    color: inherit;
}

.section-tag {
    display: inline-block;
    font-size: 0.72rem;
    font-weight: 700;
    letter-spacing: 0.14em;
    text-transform: uppercase;
    color: var(--accent);
    margin-bottom: 0.85rem;
}

/* ═══════════════════════════════════════════════════════════════
   SCROLL PROGRESS BAR
═══════════════════════════════════════════════════════════════ */
#progress {
    position: fixed;
    top: 0;
    left: 0;
    height: 2px;
    width: 0%;
    background: var(--accent);
    z-index: 9999;
    transition: width 0.08s linear;
    pointer-events: none;
}

/* ═══════════════════════════════════════════════════════════════
   NAVIGATION
═══════════════════════════════════════════════════════════════ */
#nav {
    position: fixed;
    top: 2px; /* sits just below the progress bar */
    left: 0;
    right: 0;
    z-index: 900;
    transition: background 0.35s, box-shadow 0.35s;
}

#nav.nav-scrolled {
    background: rgba(13, 27, 42, 0.96);
    backdrop-filter: blur(18px);
    -webkit-backdrop-filter: blur(18px);
    box-shadow: 0 1px 0 rgba(255, 255, 255, 0.07);
}

.nav-inner {
    max-width: 1080px;
    margin: 0 auto;
    padding: 0 2rem;
    height: 66px;
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.nav-logo {
    font-weight: 700;
    font-size: 1rem;
    letter-spacing: 0.08em;
    color: rgba(255, 255, 255, 0.9);
    transition: color 0.2s;
    flex-shrink: 0;
}
.nav-logo:hover { color: #fff; }

.nav-links {
    display: flex;
    align-items: center;
    gap: 2.25rem;
}
.nav-links a {
    font-size: 0.845rem;
    font-weight: 500;
    color: rgba(255, 255, 255, 0.65);
    transition: color 0.2s;
    position: relative;
    padding-bottom: 2px;
}
.nav-links a::after {
    content: '';
    position: absolute;
    bottom: -2px;
    left: 0;
    right: 0;
    height: 1.5px;
    background: var(--accent);
    transform: scaleX(0);
    transition: transform 0.22s ease;
    transform-origin: left;
}
.nav-links a:hover,
.nav-links a.active { color: #fff; }
.nav-links a.active::after,
.nav-links a:hover::after { transform: scaleX(1); }

/* Right-side nav cluster */
.nav-right {
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

/* Theme toggle */
.theme-toggle {
    background: none;
    border: none;
    cursor: pointer;
    color: rgba(255, 255, 255, 0.65);
    width: 36px;
    height: 36px;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: var(--radius-sm);
    transition: color 0.2s, background 0.2s;
    flex-shrink: 0;
}
.theme-toggle:hover {
    color: #fff;
    background: rgba(255, 255, 255, 0.08);
}
.theme-toggle svg { width: 17px; height: 17px; }

/* Show moon in light mode, sun in dark mode */
.icon-sun  { display: none; }
.icon-moon { display: block; }
[data-theme="dark"] .icon-sun  { display: block; }
[data-theme="dark"] .icon-moon { display: none; }

/* Burger */
.nav-burger {
    display: none;
    flex-direction: column;
    justify-content: center;
    gap: 5px;
    background: none;
    border: none;
    cursor: pointer;
    padding: 6px;
    width: 36px;
    height: 36px;
}
.nav-burger span {
    display: block;
    width: 20px;
    height: 1.5px;
    background: rgba(255, 255, 255, 0.85);
    border-radius: 2px;
    transition: transform 0.28s, opacity 0.28s;
}
.nav-burger[aria-expanded="true"] span:nth-child(1) { transform: translateY(6.5px) rotate(45deg); }
.nav-burger[aria-expanded="true"] span:nth-child(2) { opacity: 0; }
.nav-burger[aria-expanded="true"] span:nth-child(3) { transform: translateY(-6.5px) rotate(-45deg); }

/* Mobile nav */
.nav-mobile {
    display: none;
    flex-direction: column;
    background: rgba(13, 27, 42, 0.98);
    backdrop-filter: blur(18px);
    padding: 0.25rem 2rem 1.5rem;
    border-top: 1px solid rgba(255, 255, 255, 0.06);
}
.nav-mobile.open { display: flex; }
.nav-mobile a {
    font-size: 1rem;
    font-weight: 500;
    color: rgba(255, 255, 255, 0.8);
    padding: 0.75rem 0;
    border-bottom: 1px solid rgba(255, 255, 255, 0.06);
    transition: color 0.2s;
}
.nav-mobile a:last-child { border-bottom: none; }
.nav-mobile a:hover { color: #fff; }

/* ═══════════════════════════════════════════════════════════════
   HERO
═══════════════════════════════════════════════════════════════ */
#hero {
    min-height: 100vh;
    display: flex;
    align-items: center;
    position: relative;
    overflow: hidden;
    background: var(--navy);
    color: #ffffff;
    padding: 0;
}

.hero-bg {
    position: absolute;
    inset: 0;
    background:
        radial-gradient(ellipse 70% 60% at 80% 30%, rgba(79, 142, 247, 0.11) 0%, transparent 60%),
        radial-gradient(ellipse 50% 70% at 15% 85%, rgba(79, 142, 247, 0.07) 0%, transparent 60%);
    pointer-events: none;
}

/* Animated floating glow */
.hero-glow {
    position: absolute;
    width: 700px;
    height: 700px;
    border-radius: 50%;
    background: radial-gradient(circle, rgba(79, 142, 247, 0.09) 0%, transparent 65%);
    top: -100px;
    right: -50px;
    animation: heroFloat 14s ease-in-out infinite;
    pointer-events: none;
}
@keyframes heroFloat {
    0%, 100% { transform: translate(0,    0)    scale(1);    }
    33%       { transform: translate(50px, -40px) scale(1.08); }
    66%       { transform: translate(-30px, 30px) scale(0.95); }
}

/* Subtle grid */
.hero-bg::after {
    content: '';
    position: absolute;
    inset: 0;
    background-image:
        linear-gradient(rgba(79, 142, 247, 0.035) 1px, transparent 1px),
        linear-gradient(90deg, rgba(79, 142, 247, 0.035) 1px, transparent 1px);
    background-size: 64px 64px;
    mask-image: radial-gradient(ellipse 85% 85% at 50% 50%, black 0%, transparent 75%);
    -webkit-mask-image: radial-gradient(ellipse 85% 85% at 50% 50%, black 0%, transparent 75%);
}

/* Two-column hero layout */
.hero-content {
    position: relative;
    z-index: 1;
    padding-top: 7rem;
    padding-bottom: 5rem;
    display: grid;
    grid-template-columns: 1fr 360px;
    gap: 4rem;
    align-items: center;
}

.hero-eyebrow {
    font-size: 0.78rem;
    font-weight: 700;
    letter-spacing: 0.13em;
    text-transform: uppercase;
    color: var(--accent);
    margin-bottom: 1.5rem;
    opacity: 0;
    animation: fadeUp 0.7s 0.2s ease forwards;
}
.hero-text h1 {
    font-family: var(--serif);
    font-size: clamp(3rem, 7vw, 5.5rem);
    font-weight: 700;
    line-height: 1.06;
    color: #fff;
    margin-bottom: 1.75rem;
    opacity: 0;
    animation: fadeUp 0.7s 0.35s ease forwards;
}
.hero-tagline {
    font-size: clamp(1.2rem, 2.2vw, 1.55rem);
    font-weight: 300;
    color: rgba(255, 255, 255, 0.72);
    line-height: 1.45;
    margin-bottom: 0.85rem;
    opacity: 0;
    animation: fadeUp 0.7s 0.5s ease forwards;
}
.hero-sub {
    font-size: 0.78rem;
    font-weight: 600;
    letter-spacing: 0.1em;
    color: rgba(255, 255, 255, 0.32);
    margin-bottom: 2.75rem;
    opacity: 0;
    animation: fadeUp 0.7s 0.65s ease forwards;
}
.hero-actions {
    display: flex;
    gap: 1rem;
    flex-wrap: wrap;
    opacity: 0;
    animation: fadeUp 0.7s 0.8s ease forwards;
}

@keyframes fadeUp {
    from { opacity: 0; transform: translateY(18px); }
    to   { opacity: 1; transform: translateY(0); }
}

/* Photo */
.hero-photo {
    position: relative;
    display: flex;
    justify-content: center;
    animation: fadeIn 1s 0.9s ease forwards;
    opacity: 0;
}
@keyframes fadeIn {
    to { opacity: 1; }
}
.hero-photo img {
    width: 100%;
    max-width: 340px;
    aspect-ratio: 4 / 5;
    object-fit: cover;
    border-radius: 14px;
    box-shadow: 0 32px 80px rgba(0, 0, 0, 0.45), 0 0 0 1px rgba(255,255,255,0.08);
    display: block;
}
.hero-photo-placeholder {
    width: 100%;
    max-width: 340px;
    aspect-ratio: 4 / 5;
    background: rgba(255, 255, 255, 0.04);
    border: 1.5px dashed rgba(255, 255, 255, 0.14);
    border-radius: 14px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-family: var(--serif);
    font-size: 4.5rem;
    font-weight: 700;
    color: rgba(255, 255, 255, 0.12);
    letter-spacing: 0.05em;
}

/* Buttons */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 0.875rem 2rem;
    border-radius: var(--radius-sm);
    font-size: 0.875rem;
    font-weight: 600;
    letter-spacing: 0.02em;
    cursor: pointer;
    border: none;
    transition: background 0.2s, box-shadow 0.2s, transform 0.2s, border-color 0.2s, color 0.2s;
}
.btn-primary { background: var(--accent); color: #fff; }
.btn-primary:hover {
    background: var(--accent-dark);
    box-shadow: 0 6px 24px var(--accent-glow);
    transform: translateY(-1px);
}
.btn-outline {
    background: transparent;
    color: rgba(255, 255, 255, 0.82);
    border: 1.5px solid rgba(255, 255, 255, 0.28);
}
.btn-outline:hover {
    border-color: rgba(255, 255, 255, 0.65);
    color: #fff;
    background: rgba(255, 255, 255, 0.05);
}

/* Scroll cue */
.hero-scroll {
    position: absolute;
    bottom: 2.5rem;
    left: 50%;
    transform: translateX(-50%);
    color: rgba(255, 255, 255, 0.28);
    transition: color 0.2s;
    z-index: 1;
    animation: arrowBounce 2.5s 1.5s ease-in-out infinite;
}
.hero-scroll:hover { color: rgba(255, 255, 255, 0.6); }
.hero-scroll svg { width: 28px; height: 28px; }
@keyframes arrowBounce {
    0%, 100% { transform: translateX(-50%) translateY(0); }
    50%       { transform: translateX(-50%) translateY(7px); }
}

/* ═══════════════════════════════════════════════════════════════
   FOCUS AREAS
═══════════════════════════════════════════════════════════════ */
#focus {
    background: var(--bg);
    transition: background 0.3s;
}

.focus-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 1.5rem;
}

.focus-card {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 2rem 1.75rem;
    position: relative;
    overflow: hidden;
    transition: box-shadow 0.25s, transform 0.25s, background 0.3s, border-color 0.3s;
    opacity: 0;
    transform: translateY(18px);
}
.focus-card.visible { opacity: 1; transform: translateY(0); transition: opacity 0.5s, transform 0.5s, box-shadow 0.25s, background 0.3s; }
.focus-card:hover { box-shadow: var(--shadow-lg); transform: translateY(-3px); }

/* Top accent line */
.focus-card::before {
    content: '';
    position: absolute;
    top: 0; left: 0; right: 0;
    height: 2px;
    background: linear-gradient(90deg, var(--accent), transparent);
    opacity: 0;
    transition: opacity 0.25s;
}
.focus-card:hover::before { opacity: 1; }

.focus-icon {
    width: 48px;
    height: 48px;
    background: rgba(79, 142, 247, 0.1);
    border-radius: var(--radius-sm);
    display: flex;
    align-items: center;
    justify-content: center;
    margin-bottom: 1.25rem;
}
.focus-icon svg { width: 24px; height: 24px; color: var(--accent); }

.focus-card h3 {
    font-size: 1rem;
    font-weight: 700;
    color: var(--text);
    margin-bottom: 0.7rem;
    transition: color 0.3s;
}
.focus-card p {
    font-size: 0.875rem;
    color: var(--text-muted);
    line-height: 1.72;
    transition: color 0.3s;
}

/* ═══════════════════════════════════════════════════════════════
   ABOUT
═══════════════════════════════════════════════════════════════ */
.about-grid {
    display: grid;
    grid-template-columns: 1fr 320px;
    gap: 5rem;
    align-items: start;
}

.about-text p {
    margin-bottom: 1.2rem;
    color: var(--text);
    line-height: 1.82;
    font-size: 0.975rem;
    transition: color 0.3s;
}
.about-text .lead { font-size: 1.1rem; line-height: 1.75; }
.about-text p:last-child { margin-bottom: 0; }

.about-stats { display: grid; grid-template-columns: 1fr 1fr; gap: 1rem; }

.stat-card {
    background: var(--bg);
    border-radius: var(--radius);
    padding: 1.5rem 1.25rem;
    display: flex;
    flex-direction: column;
    gap: 0.4rem;
    border: 1px solid var(--border);
    transition: background 0.3s, border-color 0.3s;
    opacity: 0;
    transform: translateY(16px);
}
.stat-card.visible { opacity: 1; transform: translateY(0); transition: opacity 0.5s, transform 0.5s, background 0.3s; }

.stat-number {
    font-family: var(--serif);
    font-size: 2.1rem;
    font-weight: 700;
    color: var(--accent);
    line-height: 1;
}
.stat-label {
    font-size: 0.775rem;
    font-weight: 500;
    color: var(--text-muted);
    line-height: 1.4;
    transition: color 0.3s;
}

/* ═══════════════════════════════════════════════════════════════
   TIMELINE
═══════════════════════════════════════════════════════════════ */
.timeline {
    display: flex;
    flex-direction: column;
    position: relative;
}

/* Vertical connecting line */
.timeline::before {
    content: '';
    position: absolute;
    left: 179px;
    top: 8px;
    bottom: 8px;
    width: 1px;
    background: linear-gradient(
        to bottom,
        transparent 0%,
        rgba(79, 142, 247, 0.35) 6%,
        rgba(79, 142, 247, 0.35) 94%,
        transparent 100%
    );
    pointer-events: none;
}

.timeline-item {
    display: grid;
    grid-template-columns: 180px 1fr;
    gap: 3rem;
    padding: 2.75rem 0;
    border-top: 1px solid rgba(255, 255, 255, 0.07);
    position: relative;
    opacity: 0;
    transform: translateY(18px);
    transition: opacity 0.55s, transform 0.55s;
}
.timeline-item:first-child { border-top: none; padding-top: 0; }
.timeline-item.visible { opacity: 1; transform: translateY(0); }

/* Dot on the timeline line */
.timeline-item::before {
    content: '';
    position: absolute;
    left: 175px;
    top: 2.85rem;
    width: 9px;
    height: 9px;
    border-radius: 50%;
    background: var(--accent);
    box-shadow: 0 0 0 3px rgba(79, 142, 247, 0.18), 0 0 10px rgba(79, 142, 247, 0.25);
    z-index: 1;
}
.timeline-item:first-child::before { top: 0.1rem; }

.timeline-meta { padding-top: 0.2rem; }
.timeline-period {
    display: block;
    font-size: 0.72rem;
    font-weight: 700;
    letter-spacing: 0.1em;
    text-transform: uppercase;
    color: var(--accent);
    margin-bottom: 0.4rem;
}
.timeline-company {
    display: block;
    font-size: 0.8rem;
    font-weight: 500;
    color: rgba(255, 255, 255, 0.42);
    line-height: 1.4;
}

.timeline-body h3 {
    font-size: 1.1rem;
    font-weight: 600;
    color: #fff;
    margin-bottom: 0.8rem;
    line-height: 1.35;
}
.timeline-body p {
    font-size: 0.9rem;
    color: rgba(255, 255, 255, 0.62);
    line-height: 1.82;
    margin-bottom: 1.1rem;
}

.tags { display: flex; flex-wrap: wrap; gap: 0.45rem; }
.tags span {
    font-size: 0.7rem;
    font-weight: 600;
    padding: 0.22rem 0.8rem;
    border-radius: 100px;
    background: rgba(79, 142, 247, 0.11);
    color: var(--accent);
    letter-spacing: 0.02em;
    border: 1px solid rgba(79, 142, 247, 0.2);
}

/* ═══════════════════════════════════════════════════════════════
   SPEAKING
═══════════════════════════════════════════════════════════════ */
.speaking-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 1.5rem;
}

.speaking-card {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 2rem 1.75rem;
    opacity: 0;
    transform: translateY(18px);
    transition: opacity 0.5s, transform 0.5s, box-shadow 0.25s, background 0.3s, border-color 0.3s;
}
.speaking-card.visible { opacity: 1; transform: translateY(0); }
.speaking-card:hover { box-shadow: var(--shadow-lg); transform: translateY(-3px); }

.speaking-icon {
    width: 46px;
    height: 46px;
    background: rgba(79, 142, 247, 0.1);
    border-radius: var(--radius-sm);
    display: flex;
    align-items: center;
    justify-content: center;
    margin-bottom: 1.25rem;
}
.speaking-icon svg { width: 22px; height: 22px; color: var(--accent); }

.speaking-meta {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    flex-wrap: wrap;
    margin-bottom: 0.6rem;
}
.speaking-event {
    font-size: 0.73rem;
    font-weight: 700;
    letter-spacing: 0.08em;
    text-transform: uppercase;
    color: var(--accent);
}
.speaking-location {
    font-size: 0.73rem;
    font-weight: 500;
    color: var(--text-light);
    letter-spacing: 0.04em;
}
.speaking-card h3 {
    font-size: 0.95rem;
    font-weight: 700;
    color: var(--text);
    margin-bottom: 0.65rem;
    line-height: 1.35;
    transition: color 0.3s;
}
.speaking-card p {
    font-size: 0.875rem;
    color: var(--text-muted);
    line-height: 1.72;
    transition: color 0.3s;
}

/* ═══════════════════════════════════════════════════════════════
   EDUCATION
═══════════════════════════════════════════════════════════════ */
.education-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 1.5rem;
}

.edu-card {
    background: var(--bg-card);
    border-radius: var(--radius);
    padding: 2rem;
    border-left: 3px solid var(--accent);
    box-shadow: var(--shadow);
    transition: box-shadow 0.25s, background 0.3s;
    opacity: 0;
    transform: translateY(16px);
}
.edu-card.visible { opacity: 1; transform: translateY(0); transition: opacity 0.5s, transform 0.5s, box-shadow 0.25s; }
.edu-card:hover { box-shadow: var(--shadow-lg); }

.edu-year   { font-size: 0.72rem; font-weight: 700; color: var(--accent); letter-spacing: 0.1em; text-transform: uppercase; margin-bottom: 0.5rem; }
.edu-school { font-size: 1.05rem; font-weight: 700; color: var(--text); margin-bottom: 0.3rem; line-height: 1.3; transition: color 0.3s; }
.edu-degree { font-size: 0.875rem; color: var(--text-muted); margin-bottom: 0.75rem; line-height: 1.45; transition: color 0.3s; }
.edu-note   { font-size: 0.8rem; color: var(--text-light); font-style: italic; line-height: 1.55; transition: color 0.3s; }

/* ═══════════════════════════════════════════════════════════════
   AWARDS
═══════════════════════════════════════════════════════════════ */
.awards-list {
    display: flex;
    flex-direction: column;
    margin-bottom: 2.5rem;
}

.award-item {
    display: flex;
    align-items: flex-start;
    gap: 1.25rem;
    padding: 1.4rem 0;
    border-bottom: 1px solid var(--border);
    transition: border-color 0.3s;
    opacity: 0;
    transform: translateX(-12px);
}
.award-item.visible { opacity: 1; transform: translateX(0); transition: opacity 0.45s, transform 0.45s, border-color 0.3s; }
.award-item:first-child { border-top: 1px solid var(--border); }

.award-icon {
    width: 38px;
    height: 38px;
    background: var(--bg-alt);
    border-radius: var(--radius-sm);
    display: flex;
    align-items: center;
    justify-content: center;
    flex-shrink: 0;
    margin-top: 0.1rem;
    transition: background 0.3s;
}
.award-icon svg { width: 18px; height: 18px; color: var(--accent); }

.award-item h4 { font-size: 0.95rem; font-weight: 600; color: var(--text); margin-bottom: 0.2rem; line-height: 1.35; transition: color 0.3s; }
.award-item p  { font-size: 0.83rem; color: var(--text-muted); transition: color 0.3s; }

.patent-block {
    background: var(--bg-alt);
    border-radius: var(--radius);
    padding: 1.5rem 2rem;
    display: flex;
    align-items: center;
    gap: 1.75rem;
    flex-wrap: wrap;
    transition: background 0.3s;
}
.patent-label { font-size: 0.72rem; font-weight: 700; letter-spacing: 0.14em; text-transform: uppercase; color: var(--accent); white-space: nowrap; }
.patent-block p { font-size: 0.95rem; font-weight: 500; color: var(--text); margin: 0; transition: color 0.3s; }

/* ═══════════════════════════════════════════════════════════════
   PUBLICATIONS
═══════════════════════════════════════════════════════════════ */
.pub-list { display: flex; flex-direction: column; }

.pub-item {
    padding: 1.35rem 0;
    border-bottom: 1px solid var(--border);
    transition: border-color 0.3s;
    opacity: 0;
    transform: translateY(10px);
}
.pub-item.visible { opacity: 1; transform: translateY(0); transition: opacity 0.45s, transform 0.45s, border-color 0.3s; }
.pub-item:first-child { border-top: 1px solid var(--border); }

.pub-featured {
    background: var(--bg-card);
    border: 1px solid var(--border) !important;
    border-radius: var(--radius);
    padding: 1.5rem 1.75rem;
    box-shadow: var(--shadow);
    margin-bottom: 0.5rem;
    border-top: 1px solid var(--border) !important;
    transition: background 0.3s, border-color 0.3s;
}

.pub-badge {
    display: inline-block;
    background: var(--accent);
    color: #fff;
    font-size: 0.67rem;
    font-weight: 700;
    letter-spacing: 0.06em;
    text-transform: uppercase;
    padding: 0.22rem 0.8rem;
    border-radius: 100px;
    margin-bottom: 0.7rem;
}

.pub-item h4 { font-size: 0.925rem; font-weight: 600; color: var(--text); margin-bottom: 0.28rem; line-height: 1.4; transition: color 0.3s; }
.pub-item p  { font-size: 0.825rem; color: var(--text-muted); line-height: 1.5; transition: color 0.3s; }

/* Publication links */
.pub-item h4 a {
    color: inherit;
    text-decoration: none;
    border-bottom: 1px solid transparent;
    transition: border-color 0.2s, color 0.2s;
}
.pub-item h4 a:hover {
    color: var(--accent);
    border-bottom-color: var(--accent);
}

/* ═══════════════════════════════════════════════════════════════
   CONTACT FORM
═══════════════════════════════════════════════════════════════ */
.contact-inner { max-width: 640px; }

.contact-sub {
    font-size: 1.05rem;
    color: rgba(255, 255, 255, 0.65);
    margin-bottom: 2.5rem;
    line-height: 1.75;
}

.contact-form { margin-bottom: 2.5rem; }

.form-row {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 1rem;
    margin-bottom: 1rem;
}

.form-group {
    display: flex;
    flex-direction: column;
    gap: 0.45rem;
    margin-bottom: 1rem;
}
.form-group:last-of-type { margin-bottom: 1.5rem; }

.form-group label {
    font-size: 0.8rem;
    font-weight: 600;
    color: rgba(255, 255, 255, 0.55);
    letter-spacing: 0.04em;
    text-transform: uppercase;
}

.form-group input,
.form-group textarea {
    background: rgba(255, 255, 255, 0.06);
    border: 1px solid rgba(255, 255, 255, 0.12);
    border-radius: var(--radius-sm);
    padding: 0.8rem 1rem;
    font-family: var(--font);
    font-size: 0.9rem;
    color: rgba(255, 255, 255, 0.88);
    outline: none;
    transition: border-color 0.2s, background 0.2s;
    resize: vertical;
    width: 100%;
}
.form-group input::placeholder,
.form-group textarea::placeholder { color: rgba(255, 255, 255, 0.28); }
.form-group input:focus,
.form-group textarea:focus {
    border-color: var(--accent);
    background: rgba(255, 255, 255, 0.08);
}

.form-submit { width: 100%; justify-content: center; }
.form-submit:disabled { opacity: 0.6; cursor: not-allowed; transform: none; }

.form-success {
    font-size: 1rem;
    color: rgba(255, 255, 255, 0.75);
    padding: 1.5rem;
    background: rgba(79, 142, 247, 0.1);
    border: 1px solid rgba(79, 142, 247, 0.25);
    border-radius: var(--radius);
    text-align: center;
    line-height: 1.6;
}

/* Alternative contact links below the form */
.contact-alt {
    display: flex;
    flex-direction: column;
    gap: 0.9rem;
    margin-bottom: 2rem;
    padding-top: 0.5rem;
    border-top: 1px solid rgba(255, 255, 255, 0.08);
}

.contact-link {
    display: flex;
    align-items: center;
    gap: 0.9rem;
    font-size: 0.95rem;
    font-weight: 500;
    color: rgba(255, 255, 255, 0.72);
    transition: color 0.2s;
}
.contact-link:hover { color: #fff; }
.contact-link svg { width: 18px; height: 18px; flex-shrink: 0; opacity: 0.55; transition: opacity 0.2s; }
.contact-link:hover svg { opacity: 1; }

.contact-location { font-size: 0.8rem; color: rgba(255, 255, 255, 0.28); letter-spacing: 0.06em; }

/* ═══════════════════════════════════════════════════════════════
   FOOTER
═══════════════════════════════════════════════════════════════ */
footer { background: #070e19; padding: 1.75rem 0; }
.footer-inner {
    display: flex;
    justify-content: space-between;
    align-items: center;
    font-size: 0.78rem;
    color: rgba(255, 255, 255, 0.2);
}

/* ═══════════════════════════════════════════════════════════════
   RESPONSIVE — TABLET  (≤ 920px)
═══════════════════════════════════════════════════════════════ */
@media (max-width: 920px) {
    section { padding: 80px 0; }

    .hero-content {
        grid-template-columns: 1fr;
        padding-top: 9rem;
        padding-bottom: 6rem;
        gap: 3rem;
    }
    .hero-photo { order: -1; }
    .hero-photo img,
    .hero-photo-placeholder { max-width: 220px; aspect-ratio: 1; border-radius: 50%; }

    .about-grid    { grid-template-columns: 1fr; gap: 3.5rem; }
    .about-stats   { order: -1; grid-template-columns: repeat(4, 1fr); }

    .focus-grid    { grid-template-columns: 1fr; max-width: 480px; }
    .speaking-grid { grid-template-columns: 1fr; max-width: 480px; }
    .education-grid{ grid-template-columns: 1fr; }

    /* Hide timeline line & dots on tablet */
    .timeline::before,
    .timeline-item::before { display: none; }

    .timeline-item { grid-template-columns: 1fr; gap: 0.6rem; }
    .timeline-meta { display: flex; align-items: center; gap: 1rem; flex-wrap: wrap; }
    .timeline-period { margin-bottom: 0; }

    .form-row { grid-template-columns: 1fr; }
}

/* ═══════════════════════════════════════════════════════════════
   RESPONSIVE — MOBILE  (≤ 640px)
═══════════════════════════════════════════════════════════════ */
@media (max-width: 640px) {
    section { padding: 64px 0; }
    .section-header { margin-bottom: 2.75rem; }

    .nav-links  { display: none; }
    .nav-burger { display: flex; }

    .hero-text h1 { font-size: 2.75rem; }
    .hero-tagline { font-size: 1.2rem; }
    .hero-photo img,
    .hero-photo-placeholder { max-width: 160px; }

    .about-stats { grid-template-columns: repeat(2, 1fr); }
    .stat-number { font-size: 1.75rem; }

    .patent-block  { flex-direction: column; align-items: flex-start; gap: 0.5rem; }
    .footer-inner  { flex-direction: column; gap: 0.4rem; text-align: center; }
}

/* ═══════════════════════════════════════════════════════════════
   REDUCED MOTION
═══════════════════════════════════════════════════════════════ */
@media (prefers-reduced-motion: reduce) {
    *, *::before, *::after {
        animation-duration: 0.01ms !important;
        transition-duration: 0.01ms !important;
    }
    .timeline-item, .speaking-card, .edu-card, .award-item,
    .pub-item, .stat-card, .focus-card, .hero-photo,
    .hero-eyebrow, .hero-text h1, .hero-tagline,
    .hero-sub, .hero-actions {
        opacity: 1 !important;
        transform: none !important;
    }
}

/* ═══════════════════════════════════════════════════════════════
   HERO PHOTO GLOW
═══════════════════════════════════════════════════════════════ */
.hero-photo {
    position: relative;
}
.hero-photo::before {
    content: '';
    position: absolute;
    inset: -24px;
    border-radius: 24px;
    background: radial-gradient(ellipse at center, rgba(79, 142, 247, 0.18) 0%, transparent 70%);
    z-index: 0;
    pointer-events: none;
}
.hero-photo img,
.hero-photo-placeholder {
    position: relative;
    z-index: 1;
}

/* ═══════════════════════════════════════════════════════════════
   LANGUAGES
═══════════════════════════════════════════════════════════════ */
.languages {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    flex-wrap: wrap;
    margin-top: 1.25rem;
    padding-top: 1.25rem;
    border-top: 1px solid var(--border);
    transition: border-color 0.3s;
}
.lang-label {
    font-size: 0.72rem;
    font-weight: 700;
    letter-spacing: 0.12em;
    text-transform: uppercase;
    color: var(--text-light);
    margin-right: 0.25rem;
    transition: color 0.3s;
}
.lang-tag {
    font-size: 0.82rem;
    font-weight: 500;
    color: var(--text-muted);
    background: var(--bg-alt);
    border: 1px solid var(--border);
    border-radius: 100px;
    padding: 0.25rem 0.85rem;
    transition: background 0.3s, color 0.3s, border-color 0.3s;
}
.lang-tag em {
    font-style: normal;
    color: var(--text-light);
    margin-left: 0.3rem;
    font-size: 0.75rem;
}

/* ═══════════════════════════════════════════════════════════════
   PUBLICATION AUTHORS
═══════════════════════════════════════════════════════════════ */
.pub-authors {
    font-size: 0.78rem;
    color: var(--text-light);
    margin-top: 0.2rem;
    font-style: italic;
    transition: color 0.3s;
}

/* ═══════════════════════════════════════════════════════════════
   COPY EMAIL BUTTON
═══════════════════════════════════════════════════════════════ */
.contact-link-wrap {
    display: flex;
    align-items: center;
    gap: 0.75rem;
}
.copy-btn {
    position: relative;
    background: rgba(255, 255, 255, 0.07);
    border: 1px solid rgba(255, 255, 255, 0.12);
    border-radius: var(--radius-sm);
    color: rgba(255, 255, 255, 0.5);
    width: 34px;
    height: 34px;
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    flex-shrink: 0;
    transition: background 0.2s, color 0.2s, border-color 0.2s;
}
.copy-btn:hover {
    background: rgba(255, 255, 255, 0.12);
    color: rgba(255, 255, 255, 0.85);
    border-color: rgba(255, 255, 255, 0.25);
}
.copy-btn svg { width: 15px; height: 15px; }
.copy-tip {
    position: absolute;
    bottom: calc(100% + 6px);
    left: 50%;
    transform: translateX(-50%);
    background: var(--accent);
    color: #fff;
    font-size: 0.7rem;
    font-weight: 600;
    padding: 0.2rem 0.6rem;
    border-radius: 4px;
    white-space: nowrap;
    pointer-events: none;
    opacity: 0;
    transition: opacity 0.2s;
}
.copy-tip::after {
    content: '';
    position: absolute;
    top: 100%;
    left: 50%;
    transform: translateX(-50%);
    border: 4px solid transparent;
    border-top-color: var(--accent);
}
.copy-btn.copied .copy-tip { opacity: 1; }

/* ═══════════════════════════════════════════════════════════════
   BACK TO TOP
═══════════════════════════════════════════════════════════════ */
.back-to-top {
    position: fixed;
    bottom: 2rem;
    right: 2rem;
    width: 44px;
    height: 44px;
    border-radius: 50%;
    background: var(--accent);
    color: #fff;
    border: none;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    box-shadow: 0 4px 20px rgba(79, 142, 247, 0.4);
    opacity: 0;
    transform: translateY(12px);
    transition: opacity 0.3s, transform 0.3s, background 0.2s;
    z-index: 800;
    pointer-events: none;
}
.back-to-top.visible {
    opacity: 1;
    transform: translateY(0);
    pointer-events: auto;
}
.back-to-top:hover {
    background: var(--accent-dark);
    transform: translateY(-2px);
}
.back-to-top svg { width: 18px; height: 18px; }