/* ============================================
   Ryan Chan Portfolio — Main Stylesheet
   ============================================ */

:root {
    --color-bg: #f7f5f1;
    --color-bg-alt: #efece6;
    --color-text: #1a1a1a;
    --color-text-soft: #5a5a5a;
    --color-text-mute: #8a8680;
    --color-accent: #0a2540;
    --color-accent-hover: #143a5f;
    --color-highlight: #ff6a3d;
    --color-border: #d9d4c8;
    --color-card: #ffffff;

    --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    --font-serif: 'Fraunces', Georgia, 'Times New Roman', serif;

    --space-xs: 0.5rem;
    --space-sm: 1rem;
    --space-md: 1.5rem;
    --space-lg: 2.5rem;
    --space-xl: 4rem;
    --space-2xl: 6rem;

    --container-width: 1200px;
    --container-narrow: 880px;

    --radius-sm: 4px;
    --radius-md: 12px;
    --radius-lg: 24px;

    --transition: 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

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

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

body {
    font-family: var(--font-sans);
    background: var(--color-bg);
    color: var(--color-text);
    line-height: 1.6;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
    overflow-x: hidden;
}

a {
    color: inherit;
    text-decoration: none;
}

img {
    max-width: 100%;
    display: block;
}

ul {
    list-style: none;
}

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

/* ============================================
   NAV
   ============================================ */

.nav {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 100;
    background: rgba(247, 245, 241, 0.85);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    border-bottom: 1px solid transparent;
    transition: border-color var(--transition), background var(--transition);
}

.nav.scrolled {
    border-bottom-color: var(--color-border);
}

.nav-container {
    max-width: var(--container-width);
    margin: 0 auto;
    padding: 1rem var(--space-md);
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.nav-logo {
    font-family: var(--font-serif);
    font-size: 1.35rem;
    font-weight: 600;
    letter-spacing: -0.02em;
}

.nav-links {
    display: flex;
    gap: var(--space-lg);
    align-items: center;
}

.nav-links a {
    font-size: 0.95rem;
    color: var(--color-text-soft);
    transition: color var(--transition);
    position: relative;
}

.nav-links a:hover {
    color: var(--color-text);
}

.nav-links a::after {
    content: '';
    position: absolute;
    bottom: -4px;
    left: 0;
    width: 0;
    height: 1px;
    background: var(--color-text);
    transition: width var(--transition);
}

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

.nav-toggle {
    display: none;
    background: none;
    border: none;
    cursor: pointer;
    flex-direction: column;
    gap: 5px;
    padding: 0.5rem;
}

.nav-toggle span {
    width: 24px;
    height: 2px;
    background: var(--color-text);
    transition: var(--transition);
}

/* ============================================
   HERO
   ============================================ */

.hero {
    padding: 11rem 0 var(--space-2xl);
    position: relative;
    overflow: hidden;
}

.hero::before {
    content: '';
    position: absolute;
    top: -200px;
    right: -200px;
    width: 600px;
    height: 600px;
    background: radial-gradient(circle, rgba(255, 106, 61, 0.08) 0%, transparent 70%);
    border-radius: 50%;
    pointer-events: none;
}

.hero-container {
    max-width: var(--container-width);
    margin: 0 auto;
    padding: 0 var(--space-md);
    position: relative;
}

.hero-tag {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.4rem 0.9rem;
    background: var(--color-bg-alt);
    border: 1px solid var(--color-border);
    border-radius: 100px;
    font-size: 0.85rem;
    color: var(--color-text-soft);
    margin-bottom: var(--space-lg);
}

.hero-dot {
    width: 8px;
    height: 8px;
    background: #22c55e;
    border-radius: 50%;
    box-shadow: 0 0 0 4px rgba(34, 197, 94, 0.2);
    animation: pulse 2s ease-in-out infinite;
}

@keyframes pulse {
    0%, 100% { opacity: 1; }
    50% { opacity: 0.6; }
}

.hero-title {
    font-family: var(--font-serif);
    font-size: clamp(2.2rem, 6vw, 4.5rem);
    line-height: 1.05;
    letter-spacing: -0.03em;
    font-weight: 500;
    margin-bottom: var(--space-md);
    max-width: 960px;
}

.hero-name {
    font-weight: 700;
    color: var(--color-accent);
}

.hero-italic {
    font-style: italic;
    color: var(--color-text-soft);
    font-weight: 400;
}

.hero-subtitle {
    font-size: clamp(1rem, 1.5vw, 1.25rem);
    color: var(--color-text-soft);
    max-width: 720px;
    line-height: 1.65;
    margin-bottom: var(--space-lg);
}

.hero-cta {
    display: flex;
    gap: var(--space-sm);
    margin-bottom: var(--space-2xl);
    flex-wrap: wrap;
}

.btn {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.85rem 1.6rem;
    font-size: 0.95rem;
    font-weight: 500;
    border-radius: 100px;
    border: 1px solid transparent;
    cursor: pointer;
    transition: all var(--transition);
    text-decoration: none;
    font-family: inherit;
}

.btn-primary {
    background: var(--color-accent);
    color: white;
}

.btn-primary:hover {
    background: var(--color-accent-hover);
    transform: translateY(-2px);
    box-shadow: 0 10px 25px -10px rgba(10, 37, 64, 0.4);
}

.btn-secondary {
    background: transparent;
    color: var(--color-text);
    border-color: var(--color-border);
}

.btn-secondary:hover {
    background: var(--color-text);
    color: var(--color-bg);
    border-color: var(--color-text);
}

.hero-meta {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
    gap: var(--space-md);
    padding-top: var(--space-lg);
    border-top: 1px solid var(--color-border);
}

.hero-meta-item {
    display: flex;
    flex-direction: column;
}

.meta-value {
    font-family: var(--font-serif);
    font-size: 2.25rem;
    font-weight: 600;
    line-height: 1;
    color: var(--color-accent);
    margin-bottom: 0.25rem;
}

.meta-label {
    font-size: 0.85rem;
    color: var(--color-text-soft);
    line-height: 1.3;
}

/* ============================================
   SECTIONS
   ============================================ */

.section {
    padding: var(--space-2xl) 0;
    position: relative;
}

.section-label {
    font-size: 0.8rem;
    text-transform: uppercase;
    letter-spacing: 0.15em;
    color: var(--color-text-soft);
    margin-bottom: var(--space-md);
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.section-label::before {
    content: '';
    width: 2rem;
    height: 1px;
    background: var(--color-text-soft);
}

.section-title {
    font-family: var(--font-serif);
    font-size: clamp(1.85rem, 3.5vw, 2.75rem);
    line-height: 1.15;
    letter-spacing: -0.02em;
    font-weight: 500;
    margin-bottom: var(--space-lg);
    max-width: 880px;
}

/* ============================================
   ABOUT
   ============================================ */

.section-about {
    background: var(--color-bg-alt);
    border-top: 1px solid var(--color-border);
    border-bottom: 1px solid var(--color-border);
}

.about-grid {
    display: grid;
    grid-template-columns: 1fr 360px;
    gap: var(--space-xl);
    align-items: start;
}

.about-text p {
    color: var(--color-text-soft);
    font-size: 1.05rem;
    line-height: 1.75;
    margin-bottom: var(--space-md);
}

.about-card {
    background: var(--color-card);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-md);
    padding: var(--space-lg);
    position: sticky;
    top: 6rem;
}

.about-card h3 {
    font-family: var(--font-serif);
    font-size: 1.25rem;
    font-weight: 600;
    margin-bottom: var(--space-md);
}

.about-list li {
    display: grid;
    grid-template-columns: 110px 1fr;
    gap: var(--space-sm);
    padding: 0.75rem 0;
    border-bottom: 1px solid var(--color-border);
    font-size: 0.92rem;
}

.about-list li:last-child {
    border-bottom: none;
    padding-bottom: 0;
}

.about-list strong {
    color: var(--color-text-mute);
    font-weight: 500;
}

/* ============================================
   WORK
   ============================================ */

.work-feature {
    margin-bottom: var(--space-xl);
}

.work-feature-link {
    display: grid;
    grid-template-columns: 1.2fr 1fr;
    gap: var(--space-xl);
    background: var(--color-card);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-lg);
    padding: var(--space-xl);
    transition: all var(--transition);
    align-items: center;
}

.work-feature-link:hover {
    transform: translateY(-4px);
    box-shadow: 0 20px 50px -20px rgba(0, 0, 0, 0.15);
    border-color: var(--color-text);
}

.work-feature-meta {
    display: flex;
    align-items: center;
    gap: var(--space-sm);
    margin-bottom: var(--space-md);
}

.work-tag {
    display: inline-block;
    padding: 0.3rem 0.8rem;
    background: var(--color-accent);
    color: white;
    border-radius: 100px;
    font-size: 0.75rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

.work-year {
    font-size: 0.85rem;
    color: var(--color-text-soft);
}

.work-feature-title {
    font-family: var(--font-serif);
    font-size: clamp(1.5rem, 2.5vw, 2.25rem);
    line-height: 1.2;
    letter-spacing: -0.02em;
    margin-bottom: var(--space-sm);
    font-weight: 600;
}

.work-feature-description {
    color: var(--color-text-soft);
    line-height: 1.7;
    margin-bottom: var(--space-md);
    font-size: 1rem;
}

.work-feature-stats {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: var(--space-sm);
    margin-bottom: var(--space-md);
    padding: var(--space-md) 0;
    border-top: 1px solid var(--color-border);
    border-bottom: 1px solid var(--color-border);
}

.stat {
    display: flex;
    flex-direction: column;
    gap: 0.15rem;
}

.stat strong {
    font-family: var(--font-serif);
    font-size: 1.6rem;
    font-weight: 600;
    color: var(--color-accent);
    line-height: 1;
}

.stat span {
    font-size: 0.82rem;
    color: var(--color-text-soft);
}

.work-feature-cta {
    color: var(--color-accent);
    font-weight: 500;
    font-size: 0.95rem;
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    transition: gap var(--transition);
}

.work-feature-link:hover .work-feature-cta {
    gap: 0.8rem;
}

.work-feature-visual {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--space-sm);
    aspect-ratio: 1;
}

.visual-block {
    background: linear-gradient(135deg, var(--color-bg-alt), #ddd);
    border-radius: var(--radius-md);
    padding: var(--space-md);
    display: flex;
    flex-direction: column;
    justify-content: space-between;
    position: relative;
    overflow: hidden;
    transition: transform var(--transition);
    color: var(--color-text);
}

.visual-block::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: linear-gradient(135deg, rgba(255, 255, 255, 0.4), transparent);
    pointer-events: none;
}

.visual-1 { background: linear-gradient(135deg, #ff0050, #ff6a3d); color: white; }
.visual-2 { background: linear-gradient(135deg, #833ab4, #fd1d1d); color: white; }
.visual-3 { background: linear-gradient(135deg, #0a2540, #1e4976); color: white; }
.visual-4 { background: linear-gradient(135deg, #4a90e2, #50bfe6); color: white; }

.visual-label {
    font-size: 0.8rem;
    opacity: 0.85;
    font-weight: 500;
}

.visual-stat {
    font-family: var(--font-serif);
    font-size: 2.5rem;
    font-weight: 700;
    line-height: 1;
}

.visual-sub {
    font-size: 0.8rem;
    opacity: 0.85;
}

.work-feature-link:hover .visual-block {
    transform: scale(1.02);
}

.work-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(340px, 1fr));
    gap: var(--space-md);
}

.work-card {
    background: var(--color-card);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-md);
    padding: var(--space-lg);
    transition: all var(--transition);
    display: flex;
    flex-direction: column;
    height: 100%;
    position: relative;
    overflow: hidden;
}

.work-card::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 0;
    height: 3px;
    background: var(--color-accent);
    transition: width var(--transition);
}

.work-card:hover {
    transform: translateY(-4px);
    box-shadow: 0 20px 40px -20px rgba(0, 0, 0, 0.15);
    border-color: var(--color-text);
}

.work-card:hover::after {
    width: 100%;
}

.work-card-tag {
    display: inline-block;
    padding: 0.25rem 0.7rem;
    background: var(--color-bg-alt);
    color: var(--color-text-soft);
    border-radius: 100px;
    font-size: 0.75rem;
    font-weight: 500;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    margin-bottom: var(--space-md);
    align-self: flex-start;
}

.work-card-title {
    font-family: var(--font-serif);
    font-size: 1.4rem;
    font-weight: 600;
    margin-bottom: 0.65rem;
    line-height: 1.25;
    letter-spacing: -0.01em;
}

.work-card-description {
    color: var(--color-text-soft);
    font-size: 0.95rem;
    line-height: 1.6;
    margin-bottom: var(--space-md);
    flex-grow: 1;
}

.work-card-meta {
    font-size: 0.82rem;
    color: var(--color-text-mute);
    padding-top: var(--space-sm);
    border-top: 1px solid var(--color-border);
}

/* ============================================
   SKILLS
   ============================================ */

.section-skills {
    background: var(--color-bg-alt);
    border-top: 1px solid var(--color-border);
    border-bottom: 1px solid var(--color-border);
}

.skills-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
    gap: var(--space-md);
    margin-top: var(--space-lg);
}

.skill-block {
    background: var(--color-card);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-md);
    padding: var(--space-lg);
}

.skill-block h3 {
    font-family: var(--font-serif);
    font-size: 1.15rem;
    font-weight: 600;
    margin-bottom: var(--space-md);
    padding-bottom: var(--space-sm);
    border-bottom: 1px solid var(--color-border);
}

.skill-block ul li {
    padding: 0.4rem 0;
    font-size: 0.92rem;
    color: var(--color-text-soft);
}

/* ============================================
   EXPERIENCE
   ============================================ */

.timeline {
    margin-top: var(--space-lg);
    position: relative;
    padding-left: 0;
}

.timeline-item {
    display: grid;
    grid-template-columns: 200px 1fr;
    gap: var(--space-lg);
    padding: var(--space-lg) 0;
    border-top: 1px solid var(--color-border);
    align-items: start;
}

.timeline-item:first-child {
    border-top: none;
    padding-top: 0;
}

.timeline-date {
    font-size: 0.9rem;
    color: var(--color-text-mute);
    font-variant-numeric: tabular-nums;
    padding-top: 0.4rem;
}

.timeline-content h3 {
    font-family: var(--font-serif);
    font-size: 1.35rem;
    font-weight: 600;
    margin-bottom: 0.25rem;
}

.timeline-company {
    color: var(--color-text-soft);
    margin-bottom: var(--space-sm);
    font-size: 0.95rem;
}

.timeline-content ul {
    list-style: disc;
    padding-left: 1.2rem;
}

.timeline-content ul li {
    color: var(--color-text-soft);
    font-size: 0.95rem;
    line-height: 1.65;
    margin-bottom: 0.5rem;
}

.education-block,
.certifications-block {
    margin-top: var(--space-xl);
    padding-top: var(--space-xl);
    border-top: 1px solid var(--color-border);
}

.education-block h3,
.certifications-block h3 {
    font-family: var(--font-serif);
    font-size: 1.5rem;
    font-weight: 600;
    margin-bottom: var(--space-md);
}

.education-degree {
    font-weight: 600;
    font-size: 1.1rem;
    margin-bottom: 0.25rem;
}

.education-school {
    color: var(--color-text-soft);
    margin-bottom: var(--space-sm);
}

.education-courses {
    color: var(--color-text-soft);
    font-size: 0.95rem;
    line-height: 1.7;
}

.cert-list li {
    padding: 0.5rem 0;
    font-size: 0.95rem;
    color: var(--color-text-soft);
}

/* ============================================
   CONTACT
   ============================================ */

.section-contact {
    background: var(--color-accent);
    color: white;
}

.section-contact .section-label {
    color: rgba(255, 255, 255, 0.7);
}

.section-contact .section-label::before {
    background: rgba(255, 255, 255, 0.5);
}

.contact-title {
    color: white;
}

.contact-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
    gap: var(--space-md);
    margin-top: var(--space-lg);
}

.contact-card {
    background: rgba(255, 255, 255, 0.05);
    border: 1px solid rgba(255, 255, 255, 0.15);
    border-radius: var(--radius-md);
    padding: var(--space-lg);
    transition: all var(--transition);
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}

a.contact-card:hover {
    background: rgba(255, 255, 255, 0.1);
    border-color: rgba(255, 255, 255, 0.3);
    transform: translateY(-2px);
}

.contact-label {
    font-size: 0.8rem;
    text-transform: uppercase;
    letter-spacing: 0.1em;
    color: rgba(255, 255, 255, 0.6);
}

.contact-value {
    font-size: 1.05rem;
    font-weight: 500;
    color: white;
    word-break: break-word;
}

/* ============================================
   FOOTER
   ============================================ */

.footer {
    background: var(--color-bg);
    padding: var(--space-lg) 0;
    border-top: 1px solid var(--color-border);
}

.footer-container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
    gap: var(--space-md);
}

.footer-name {
    font-family: var(--font-serif);
    font-size: 1.15rem;
    font-weight: 600;
}

.footer-tagline {
    font-size: 0.85rem;
    color: var(--color-text-soft);
}

.footer-right {
    font-size: 0.85rem;
    color: var(--color-text-soft);
}

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

@media (max-width: 900px) {
    .work-feature-link {
        grid-template-columns: 1fr;
        padding: var(--space-lg);
    }

    .work-feature-visual {
        aspect-ratio: 1.4;
        max-height: 360px;
    }

    .about-grid {
        grid-template-columns: 1fr;
    }

    .about-card {
        position: static;
    }

    .timeline-item {
        grid-template-columns: 1fr;
        gap: var(--space-sm);
    }

    .nav-links {
        display: none;
        position: absolute;
        top: 100%;
        left: 0;
        right: 0;
        background: var(--color-bg);
        flex-direction: column;
        padding: var(--space-md);
        gap: var(--space-sm);
        border-bottom: 1px solid var(--color-border);
    }

    .nav-links.open {
        display: flex;
    }

    .nav-toggle {
        display: flex;
    }

    .hero {
        padding-top: 8rem;
    }

    .work-feature-stats {
        grid-template-columns: 1fr 1fr;
    }
}

@media (max-width: 560px) {
    .hero-cta {
        flex-direction: column;
    }

    .btn {
        width: 100%;
        justify-content: center;
    }

    .visual-stat {
        font-size: 1.85rem;
    }

    .work-feature-visual {
        aspect-ratio: 1;
    }
}

/* ============================================
   ANIMATIONS
   ============================================ */

.fade-in {
    opacity: 0;
    transform: translateY(20px);
    transition: opacity 0.6s ease, transform 0.6s ease;
}

.fade-in.visible {
    opacity: 1;
    transform: translateY(0);
}