/* ========================================
   Design Tokens
   ======================================== */
:root {
    --font-display: 'Cormorant Garamond', 'Georgia', 'Times New Roman', serif;
    --font-body: 'Karla', -apple-system, BlinkMacSystemFont, sans-serif;

    --color-bg: #f8f6f1;
    --color-bg-nav: rgba(248, 246, 241, 0.88);

    --color-text: #1a1a1a;
    --color-text-secondary: #4a4a4a;
    --color-text-muted: #8c8c8c;

    --color-accent: #9b2335;
    --color-accent-hover: #7d1c2b;
    --color-accent-soft: rgba(155, 35, 53, 0.05);

    --color-border: #e4dfd6;
    --color-border-light: #eeebe5;

    --shadow-sm: 0 2px 8px rgba(30, 20, 15, 0.06);
    --shadow-md: 0 4px 20px rgba(30, 20, 15, 0.08);

    --ease-out: cubic-bezier(0.0, 0.0, 0.2, 1);
    --transition-fast: 0.2s cubic-bezier(0.0, 0.0, 0.2, 1);
    --transition-normal: 0.35s cubic-bezier(0.0, 0.0, 0.2, 1);
}

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

html {
    scroll-behavior: smooth;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
    scrollbar-width: thin;
    scrollbar-color: var(--color-border) var(--color-bg);
}

body {
    font-family: var(--font-body);
    background-color: var(--color-bg);
    background-image:
        radial-gradient(ellipse at 15% 0%, rgba(155, 35, 53, 0.025) 0%, transparent 50%),
        radial-gradient(ellipse at 85% 100%, rgba(155, 35, 53, 0.015) 0%, transparent 50%);
    color: var(--color-text);
    line-height: 1.65;
    font-size: 15px;
    min-height: 100vh;
}

::selection {
    background-color: rgba(155, 35, 53, 0.12);
    color: var(--color-text);
}

a {
    color: var(--color-accent);
    text-decoration: none;
    transition: color var(--transition-fast);
}

a:hover {
    color: var(--color-accent-hover);
}

/* Scrollbar (Webkit) */
::-webkit-scrollbar {
    width: 7px;
}

::-webkit-scrollbar-track {
    background: var(--color-bg);
}

::-webkit-scrollbar-thumb {
    background: var(--color-border);
    border-radius: 4px;
}

::-webkit-scrollbar-thumb:hover {
    background: var(--color-text-muted);
}

/* ========================================
   Navigation Bar
   ======================================== */
.navbar {
    position: sticky;
    top: 0;
    background-color: var(--color-bg-nav);
    backdrop-filter: blur(16px) saturate(180%);
    -webkit-backdrop-filter: blur(16px) saturate(180%);
    border-bottom: 1px solid var(--color-border-light);
    z-index: 100;
}

.nav-container {
    max-width: 1100px;
    margin: 0 auto;
    padding: 0 32px;
    display: flex;
    align-items: center;
    height: 54px;
    gap: 32px;
}

.nav-link {
    position: relative;
    color: var(--color-text-muted);
    font-family: var(--font-body);
    font-weight: 500;
    font-size: 13.5px;
    letter-spacing: 0.015em;
    padding: 4px 0;
    text-decoration: none;
    transition: color var(--transition-fast);
    cursor: pointer;
}

.nav-link::after {
    content: '';
    position: absolute;
    bottom: -2px;
    left: 0;
    width: 0;
    height: 2px;
    background-color: var(--color-accent);
    border-radius: 1px;
    transition: width var(--transition-normal);
}

.nav-link:hover {
    color: var(--color-text-secondary);
    text-decoration: none;
}

.nav-link:hover::after {
    width: 100%;
}

.nav-link.active {
    color: var(--color-accent);
    font-weight: 600;
}

.nav-link.active::after {
    width: 100%;
}

/* ========================================
   Main Layout
   ======================================== */
.container {
    max-width: 1100px;
    margin: 0 auto;
    display: grid;
    grid-template-columns: 256px 1fr;
    gap: 56px;
    padding: 48px 32px 96px;
}

/* ========================================
   Sidebar Profile Card
   ======================================== */
.sidebar {
    grid-column: 1;
}

.profile-card {
    position: sticky;
    top: 86px;
    padding: 0;
}

.profile-card > * {
    opacity: 0;
    transform: translateY(12px);
    animation: profileReveal 0.6s var(--ease-out) forwards;
}

.profile-card > *:nth-child(1) { animation-delay: 0.1s; }
.profile-card > *:nth-child(2) { animation-delay: 0.2s; }
.profile-card > *:nth-child(3) { animation-delay: 0.28s; }
.profile-card > *:nth-child(4) { animation-delay: 0.36s; }
.profile-card > *:nth-child(5) { animation-delay: 0.44s; }

@keyframes profileReveal {
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.avatar {
    width: 100%;
    max-width: 220px;
    border-radius: 14px;
    margin-bottom: 24px;
    display: block;
    box-shadow: var(--shadow-md);
    transition: box-shadow var(--transition-normal), transform var(--transition-normal);
}

.avatar:hover {
    box-shadow: 0 8px 28px rgba(30, 20, 15, 0.12);
    transform: translateY(-2px);
}

.name {
    font-family: var(--font-display);
    font-size: 26px;
    font-weight: 700;
    color: var(--color-text);
    margin-bottom: 4px;
    letter-spacing: -0.01em;
    line-height: 1.2;
}

.affiliation {
    font-family: var(--font-body);
    font-size: 14px;
    color: var(--color-text-muted);
    font-weight: 500;
    letter-spacing: 0.01em;
    margin-bottom: 20px;
}

.contact-info {
    margin-bottom: 20px;
    border-top: 1px solid var(--color-border-light);
    border-bottom: 1px solid var(--color-border-light);
    padding: 16px 0;
}

.contact-info p {
    font-size: 13.5px;
    color: var(--color-text-secondary);
    margin-bottom: 10px;
    line-height: 1.5;
}

.contact-info p:last-child {
    margin-bottom: 0;
}

.contact-info strong {
    color: var(--color-text-muted);
    font-weight: 600;
    text-transform: uppercase;
    font-size: 10px;
    letter-spacing: 0.08em;
    display: block;
    margin-bottom: 1px;
}

.contact-info a {
    word-break: break-all;
    font-size: 13.5px;
}

.social-links {
    display: flex;
    gap: 10px;
}

.social-link {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 8px 20px;
    background-color: transparent;
    border: 1.5px solid var(--color-border);
    border-radius: 8px;
    color: var(--color-text-secondary);
    font-size: 13px;
    font-weight: 600;
    letter-spacing: 0.02em;
    text-align: center;
    transition: all var(--transition-fast);
    flex: 1;
}

.social-link:hover {
    background-color: var(--color-accent);
    color: #ffffff;
    border-color: var(--color-accent);
    text-decoration: none;
    transform: translateY(-1px);
    box-shadow: 0 4px 12px rgba(155, 35, 53, 0.2);
}

/* ========================================
   Main Content
   ======================================== */
.content {
    grid-column: 2;
}

.section-home,
.section-papers,
.section-experience,
.section-honors,
.section-publications {
    margin-bottom: 56px;
    scroll-margin-top: 76px;
}

/* About Me entrance animation */
.section-home {
    animation: sectionFadeUp 0.7s var(--ease-out) 0.15s both;
}

@keyframes sectionFadeUp {
    from {
        opacity: 0;
        transform: translateY(24px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.content h2 {
    font-family: var(--font-display);
    font-size: 32px;
    font-weight: 600;
    color: var(--color-text);
    margin-bottom: 24px;
    padding-left: 16px;
    border-left: 3px solid var(--color-accent);
    line-height: 1.2;
    letter-spacing: -0.01em;
}

.content > section > p {
    font-size: 15px;
    line-height: 1.78;
    color: var(--color-text-secondary);
    margin-bottom: 12px;
    max-width: 620px;
}

/* ========================================
   Timeline
   ======================================== */
.timeline {
    list-style: none;
    padding: 0;
}

.timeline-item {
    display: flex;
    padding: 18px 12px;
    margin: 0 -12px;
    border-bottom: 1px solid var(--color-border-light);
    border-radius: 6px;
    transition: background-color var(--transition-fast);
}

.timeline-item:last-child {
    border-bottom: none;
}

.timeline-item:hover {
    background-color: var(--color-accent-soft);
}

.date {
    min-width: 110px;
    color: var(--color-accent);
    font-weight: 600;
    font-size: 12px;
    letter-spacing: 0.04em;
    text-transform: uppercase;
    margin-right: 24px;
    flex-shrink: 0;
    padding-top: 3px;
}

.timeline-item > .content {
    flex: 1;
    font-size: 15px;
    line-height: 1.65;
    color: var(--color-text);
    font-weight: 500;
}

.timeline-item em {
    color: var(--color-text-muted);
    font-style: italic;
    display: block;
    margin-top: 4px;
    font-size: 13.5px;
    font-weight: 400;
    line-height: 1.5;
}

.timeline-item a {
    display: inline-block;
    margin-right: 10px;
    margin-top: 6px;
    font-size: 12.5px;
    font-weight: 600;
    letter-spacing: 0.01em;
    padding: 3px 10px;
    border-radius: 4px;
    background-color: var(--color-accent-soft);
    color: var(--color-accent);
    transition: all var(--transition-fast);
}

.timeline-item a:hover {
    background-color: var(--color-accent);
    color: #fff;
    text-decoration: none;
}

/* ========================================
   Scroll Reveal
   ======================================== */
.reveal {
    opacity: 0;
    transform: translateY(24px);
    transition: opacity 0.65s var(--ease-out), transform 0.65s var(--ease-out);
}

.reveal.revealed {
    opacity: 1;
    transform: translateY(0);
}

.reveal .timeline-item {
    opacity: 0;
    transform: translateY(12px);
    transition: opacity 0.5s var(--ease-out), transform 0.5s var(--ease-out);
}

.reveal.revealed .timeline-item {
    opacity: 1;
    transform: translateY(0);
}

.reveal.revealed .timeline-item:nth-child(1) { transition-delay: 0.06s; }
.reveal.revealed .timeline-item:nth-child(2) { transition-delay: 0.12s; }
.reveal.revealed .timeline-item:nth-child(3) { transition-delay: 0.18s; }
.reveal.revealed .timeline-item:nth-child(4) { transition-delay: 0.24s; }
.reveal.revealed .timeline-item:nth-child(5) { transition-delay: 0.30s; }
.reveal.revealed .timeline-item:nth-child(6) { transition-delay: 0.36s; }

/* ========================================
   Reduced Motion
   ======================================== */
@media (prefers-reduced-motion: reduce) {
    *,
    *::before,
    *::after {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !important;
    }

    .reveal,
    .reveal .timeline-item,
    .profile-card > * {
        opacity: 1 !important;
        transform: none !important;
    }
}

/* ========================================
   Responsive - Mobile (< 768px)
   ======================================== */
@media (max-width: 768px) {
    .nav-container {
        flex-wrap: wrap;
        height: auto;
        padding: 10px 16px;
        gap: 4px 14px;
    }

    .nav-link {
        font-size: 12.5px;
        padding: 6px 0;
    }

    .container {
        grid-template-columns: 1fr;
        gap: 24px;
        padding: 24px 16px 60px;
    }

    .sidebar {
        grid-column: 1;
    }

    .profile-card {
        position: static;
        text-align: center;
    }

    .avatar {
        max-width: 120px;
        margin: 0 auto 16px;
        border-radius: 12px;
    }

    .name {
        font-size: 22px;
    }

    .affiliation {
        margin-bottom: 16px;
    }

    .contact-info {
        text-align: left;
    }

    .content {
        grid-column: 1;
    }

    .content h2 {
        font-size: 26px;
        margin-bottom: 20px;
    }

    .section-home,
    .section-papers,
    .section-experience,
    .section-honors,
    .section-publications {
        margin-bottom: 40px;
    }

    .timeline-item {
        flex-direction: column;
        padding: 14px 8px;
        margin: 0 -8px;
    }

    .date {
        min-width: auto;
        margin-right: 0;
        margin-bottom: 4px;
    }

    .content > section > p {
        font-size: 14px;
    }

    .social-links {
        justify-content: center;
        gap: 8px;
    }

    .social-link {
        flex: 0 1 auto;
        padding: 8px 24px;
    }
}

/* ========================================
   Responsive - Tablet (768px - 1024px)
   ======================================== */
@media (max-width: 1024px) and (min-width: 769px) {
    .container {
        grid-template-columns: 220px 1fr;
        gap: 36px;
        padding: 36px 24px 72px;
    }

    .profile-card {
        top: 86px;
    }

    .nav-container {
        gap: 24px;
    }

    .nav-link {
        font-size: 13px;
    }

    .content h2 {
        font-size: 28px;
    }
}

/* ========================================
   Print
   ======================================== */
@media print {
    .navbar {
        display: none;
    }

    .container {
        max-width: 100%;
        padding: 0;
    }

    body {
        background: #fff;
        background-image: none;
    }

    .reveal,
    .reveal .timeline-item,
    .profile-card > * {
        opacity: 1 !important;
        transform: none !important;
        animation: none !important;
    }

    a {
        color: #000;
    }
}