/* ==================== Base Custom Properties (theme-independent) ==================== */
:root {
    /* Spacing */
    --spacing-xs: 0.5rem;
    --spacing-sm: 1rem;
    --spacing-md: 2rem;
    --spacing-lg: 4rem;
    --spacing-xl: 6rem;

    /* Typography */
    --font-primary: 'IBM Plex Sans', -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Roboto', sans-serif;
    --font-mono: 'IBM Plex Mono', ui-monospace, SFMono-Regular, Menlo, monospace;

    /* Radii — restrained, institutional (not pill-shaped) */
    --radius-sm: 4px;
    --radius: 6px;
    --radius-md: 8px;
    --radius-lg: 10px;

    /* Transitions */
    --transition-fast: all 0.2s cubic-bezier(0.4, 0, 0.2, 1);
    --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    --transition-slow: all 0.6s cubic-bezier(0.4, 0, 0.2, 1);
    --transition-theme: background-color 0.35s ease, color 0.35s ease, border-color 0.35s ease, box-shadow 0.35s ease;
}

/* ==================== Dark Theme ==================== */
[data-theme="dark"] {
    /* Backgrounds — flat ink navy, no gradient */
    --color-bg: #0a0f1c;
    --color-bg-section-alt: #0d1424;
    --color-bg-card: #101829;
    --color-bg-card-hover: #141d31;
    --color-bg-nav: rgba(10, 15, 28, 0.85);
    --color-bg-nav-scrolled: rgba(10, 15, 28, 0.95);
    --color-bg-footer: #0d1424;
    --color-bg-metrics-panel: rgba(148, 163, 184, 0.05);
    --color-bg-hero-label: rgba(79, 142, 247, 0.1);
    --color-bg-skill-tag: rgba(148, 163, 184, 0.07);
    --color-bg-tag: rgba(148, 163, 184, 0.06);
    --color-bg-hero-metrics: transparent;
    --color-hero-overlay: none;

    /* Text */
    --color-text: #cbd5e1;
    --color-text-secondary: #8b9ab1;
    --color-heading: #f8fafc;

    /* Borders — hairlines, not colour washes */
    --color-border: rgba(148, 163, 184, 0.14);
    --color-border-nav: rgba(148, 163, 184, 0.12);
    --color-border-hover: rgba(79, 142, 247, 0.45);
    --color-border-footer: rgba(148, 163, 184, 0.12);
    --color-border-tag: rgba(148, 163, 184, 0.18);
    --color-border-metrics-divider: rgba(148, 163, 184, 0.16);

    /* Accent — single institutional blue */
    --color-accent: #4f8ef7;
    --color-accent-hover: #6ba1f9;
    --color-on-accent: #0a0f1c;
    --color-accent-dim: rgba(79, 142, 247, 0.1);
    --color-accent-purple: rgba(148, 163, 184, 0.2);
    --color-accent-purple-light: #4f8ef7;

    /* Shadows — neutral and tight, no coloured glow */
    --color-shadow-nav: 0 1px 3px rgba(0, 0, 0, 0.4);
    --color-shadow-card-hover: 0 8px 24px rgba(0, 0, 0, 0.45);
    --color-shadow-btn-primary: 0 1px 2px rgba(0, 0, 0, 0.4);
    --color-shadow-btn-secondary: 0 1px 2px rgba(0, 0, 0, 0.3);
    --color-shadow-skill-hover: 0 6px 18px rgba(0, 0, 0, 0.35);
    --color-shadow-contact-hover: 0 8px 22px rgba(0, 0, 0, 0.4);
    --color-shadow-skill-tag: none;

    /* Logo — no glow */
    --color-logo-shadow: none;
    --color-logo-shadow-hover: none;

    /* Theme toggle */
    --color-toggle-bg: rgba(148, 163, 184, 0.08);
    --color-toggle-bg-hover: rgba(148, 163, 184, 0.16);
    --color-toggle-border: rgba(148, 163, 184, 0.18);
    --color-toggle-icon: #cbd5e1;

    /* Icon visibility */
    --icon-sun-display: flex;
    --icon-moon-display: none;
}

/* ==================== Light Theme ==================== */
[data-theme="light"] {
    /* Backgrounds — flat white, no gradient */
    --color-bg: #ffffff;
    --color-bg-section-alt: #f8fafc;
    --color-bg-card: #ffffff;
    --color-bg-card-hover: #ffffff;
    --color-bg-nav: rgba(255, 255, 255, 0.85);
    --color-bg-nav-scrolled: rgba(255, 255, 255, 0.95);
    --color-bg-footer: #f8fafc;
    --color-bg-metrics-panel: #f8fafc;
    --color-bg-hero-label: rgba(29, 78, 216, 0.07);
    --color-bg-skill-tag: #f1f5f9;
    --color-bg-tag: #f1f5f9;
    --color-bg-hero-metrics: transparent;
    --color-hero-overlay: none;

    /* Text */
    --color-text: #334155;
    --color-text-secondary: #64748b;
    --color-heading: #0b1220;

    /* Borders — hairlines */
    --color-border: #e2e8f0;
    --color-border-nav: #e2e8f0;
    --color-border-hover: rgba(29, 78, 216, 0.4);
    --color-border-footer: #e2e8f0;
    --color-border-tag: #e2e8f0;
    --color-border-metrics-divider: #e2e8f0;

    /* Accent — single institutional blue */
    --color-accent: #1d4ed8;
    --color-accent-hover: #1e40af;
    --color-on-accent: #ffffff;
    --color-accent-dim: rgba(29, 78, 216, 0.06);
    --color-accent-purple: #e2e8f0;
    --color-accent-purple-light: #1d4ed8;

    /* Shadows — neutral and tight, no coloured glow */
    --color-shadow-nav: 0 1px 3px rgba(2, 6, 23, 0.06);
    --color-shadow-card-hover: 0 4px 16px rgba(2, 6, 23, 0.08);
    --color-shadow-btn-primary: 0 1px 2px rgba(2, 6, 23, 0.1);
    --color-shadow-btn-secondary: 0 1px 2px rgba(2, 6, 23, 0.06);
    --color-shadow-skill-hover: 0 4px 14px rgba(2, 6, 23, 0.07);
    --color-shadow-contact-hover: 0 4px 16px rgba(2, 6, 23, 0.08);
    --color-shadow-skill-tag: none;

    /* Logo glow — flat in light mode */
    --color-logo-shadow: none;
    --color-logo-shadow-hover: none;

    /* Theme toggle */
    --color-toggle-bg: #f1f5f9;
    --color-toggle-bg-hover: #e2e8f0;
    --color-toggle-border: #e2e8f0;
    --color-toggle-icon: #475569;

    /* Icon visibility */
    --icon-sun-display: none;
    --icon-moon-display: flex;
}

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

html {
    scroll-behavior: smooth;
}

body {
    font-family: var(--font-primary);
    background: var(--color-bg);
    color: var(--color-text);
    line-height: 1.6;
    overflow-x: hidden;
    transition: var(--transition-theme);
    min-height: 100vh;
}

h1, h2, h3, h4, h5, h6 {
    color: var(--color-heading);
    font-weight: 600;
    letter-spacing: -0.015em;
    transition: color 0.35s ease;
}

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

/* ==================== Navigation ==================== */
.nav {
    position: fixed;
    top: 0;
    width: 100%;
    background: var(--color-bg-nav);
    border-bottom: 1px solid var(--color-border-nav);
    box-shadow: var(--color-shadow-nav);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    z-index: 1000;
    transition: var(--transition);
}

.nav.scrolled {
    background: var(--color-bg-nav-scrolled);
}

.nav-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 1.1rem 2rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
    gap: 1rem;
}

.logo {
    font-size: 1.6rem;
    font-weight: 700;
    color: var(--color-heading);
    text-decoration: none;
    text-shadow: var(--color-logo-shadow);
    transition: var(--transition);
    flex-shrink: 0;
}

.logo:hover {
    color: var(--color-accent);
    text-shadow: var(--color-logo-shadow-hover);
}

.nav-menu {
    display: flex;
    list-style: none;
    gap: 1.5rem;
    align-items: center;
}

.nav-menu li:not(:last-child)::after {
    content: '|';
    color: var(--color-border-nav);
    margin-left: 1.5rem;
    font-weight: 300;
}

.nav-link {
    color: var(--color-heading);
    text-decoration: none;
    font-weight: 600;
    font-size: 1rem;
    transition: var(--transition);
    position: relative;
    padding-bottom: 2px;
}

.nav-link::after {
    content: '';
    position: absolute;
    bottom: -4px;
    left: 0;
    width: 0;
    height: 2px;
    background: var(--color-accent);
    transition: var(--transition);
}

.nav-link:hover,
.nav-link.active {
    color: var(--color-accent);
}

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

/* Nav actions: theme toggle + hamburger */
.nav-actions {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    flex-shrink: 0;
}

/* ==================== Theme Toggle ==================== */
.theme-toggle {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 40px;
    height: 40px;
    border-radius: var(--radius);
    background: var(--color-toggle-bg);
    border: 1.5px solid var(--color-toggle-border);
    color: var(--color-toggle-icon);
    cursor: pointer;
    transition: var(--transition);
    padding: 0;
    flex-shrink: 0;
}

.theme-toggle:hover {
    background: var(--color-toggle-bg-hover);
    transform: rotate(15deg) scale(1.08);
}

.theme-toggle .icon-sun {
    display: var(--icon-sun-display, flex);
}

.theme-toggle .icon-moon {
    display: var(--icon-moon-display, none);
}

/* ==================== Mobile Hamburger ==================== */
.mobile-toggle {
    display: none;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    width: 40px;
    height: 40px;
    gap: 5px;
    background: var(--color-toggle-bg);
    border: 1.5px solid var(--color-toggle-border);
    border-radius: var(--radius);
    cursor: pointer;
    padding: 0;
    transition: var(--transition);
}

.mobile-toggle span {
    display: block;
    width: 20px;
    height: 2px;
    background: var(--color-toggle-icon);
    border-radius: 2px;
    transition: var(--transition);
    transform-origin: center;
}

.mobile-toggle.active span:nth-child(1) {
    transform: translateY(7px) rotate(45deg);
}
.mobile-toggle.active span:nth-child(2) {
    opacity: 0;
    transform: scaleX(0);
}
.mobile-toggle.active span:nth-child(3) {
    transform: translateY(-7px) rotate(-45deg);
}

/* ==================== Hero Section ==================== */
.hero {
    min-height: 100vh;
    display: flex;
    align-items: center;
    padding: 100px 2rem 5rem;
    position: relative;
    overflow: hidden;
}

.hero::before {
    content: '';
    position: absolute;
    inset: 0;
    background: var(--color-hero-overlay);
    pointer-events: none;
    z-index: 0;
    transition: var(--transition-theme);
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    width: 100%;
    position: relative;
    z-index: 1;
}

.hero-label {
    display: inline-block;
    padding: 0.4rem 0.75rem;
    background: var(--color-bg-hero-label);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-sm);
    color: var(--color-accent);
    font-family: var(--font-mono);
    font-size: 0.75rem;
    font-weight: 500;
    margin-bottom: 1.25rem;
    text-transform: uppercase;
    letter-spacing: 0.08em;
    animation: fadeInDown 0.8s ease-out;
    transition: var(--transition-theme);
}

.hero-title {
    font-size: clamp(2.25rem, 6vw, 3.75rem);
    font-weight: 600;
    line-height: 1.12;
    letter-spacing: -0.03em;
    margin-bottom: 1.5rem;
    animation: fadeInUp 0.8s ease-out 0.2s backwards;
}

.gradient-text {
    color: var(--color-accent);
}

@keyframes gradientShift {
    0%, 100% { background-position: 0% center; }
    50% { background-position: 100% center; }
}

.hero-description {
    font-size: 1.2rem;
    color: var(--color-text-secondary);
    margin-bottom: 2rem;
    max-width: 600px;
    line-height: 1.8;
    animation: fadeInUp 0.8s ease-out 0.4s backwards;
    transition: color 0.35s ease;
}

.btn-group {
    display: flex;
    gap: 1rem;
    flex-wrap: wrap;
    animation: fadeInUp 0.8s ease-out 0.6s backwards;
    margin-bottom: 2.5rem;
}

/* Hero metrics strip */
.hero-metrics {
    display: flex;
    align-items: stretch;
    gap: 0;
    background: var(--color-bg-hero-metrics);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-md);
    padding: 1.5rem 1rem;
    max-width: 820px;
    animation: fadeInUp 0.8s ease-out 0.8s backwards;
    transition: var(--transition-theme);
}

.hero-metric {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: flex-start;
    flex: 1;
    gap: 0.5rem;
    padding: 0 0.75rem;
}

.hero-metric-value {
    font-size: 1.35rem;
    font-weight: 600;
    color: var(--color-heading);
    line-height: 1.15;
    white-space: nowrap;
    font-variant-numeric: tabular-nums;
    letter-spacing: -0.02em;
    transition: color 0.35s ease;
}

.hero-metric-label {
    font-family: var(--font-mono);
    font-size: 0.7rem;
    color: var(--color-text-secondary);
    text-align: center;
    font-weight: 400;
    text-transform: uppercase;
    letter-spacing: 0.06em;
    transition: color 0.35s ease;
}

.hero-metric-divider {
    width: 1px;
    height: 36px;
    background: var(--color-border-metrics-divider);
    flex-shrink: 0;
    transition: background 0.35s ease;
}

/* ==================== Buttons ==================== */
.btn {
    padding: 0.875rem 1.875rem;
    border-radius: var(--radius);
    font-weight: 600;
    font-size: 0.95rem;
    text-decoration: none;
    transition: var(--transition);
    display: inline-block;
    border: none;
    cursor: pointer;
    position: relative;
    overflow: hidden;
    font-family: var(--font-primary);
}

.btn-primary {
    background: var(--color-accent);
    color: var(--color-on-accent);
    font-weight: 600;
}

.btn-primary:hover {
    background: var(--color-accent-hover);
    transform: translateY(-1px);
    box-shadow: var(--color-shadow-btn-primary);
    color: var(--color-on-accent);
}

.btn-secondary {
    background: transparent;
    color: var(--color-text);
    border: 1px solid var(--color-border);
    transition: var(--transition);
}

.btn-secondary:hover {
    border-color: var(--color-accent);
    background: var(--color-accent-dim);
    transform: translateY(-3px);
    box-shadow: var(--color-shadow-btn-secondary);
}

/* ==================== Sections ==================== */
section {
    padding: var(--spacing-xl) 2rem;
}

.section-header {
    text-align: center;
    margin-bottom: var(--spacing-lg);
}

.section-label {
    color: var(--color-accent);
    font-family: var(--font-mono);
    font-weight: 500;
    text-transform: uppercase;
    font-size: 0.75rem;
    margin-bottom: 0.5rem;
    display: block;
    letter-spacing: 0.08em;
    transition: color 0.35s ease;
}

.section-title {
    font-size: clamp(1.75rem, 4vw, 2.5rem);
    font-weight: 600;
    letter-spacing: -0.02em;
    margin-bottom: var(--spacing-sm);
}

.section-subtitle {
    max-width: 700px;
    margin: 0.75rem auto 0;
    color: var(--color-text-secondary);
    font-size: 1.05rem;
    line-height: 1.7;
    transition: color 0.35s ease;
}

/* ==================== About Section ==================== */
.about {
    background: var(--color-bg-section-alt);
    backdrop-filter: blur(10px);
    -webkit-backdrop-filter: blur(10px);
    transition: var(--transition-theme);
}

.about-text {
    max-width: 900px;
    margin: 0 auto;
    padding: 2.5rem;
    background: var(--color-bg-card);
    border: 1.5px solid var(--color-border);
    border-radius: var(--radius-md);
    backdrop-filter: blur(10px);
    -webkit-backdrop-filter: blur(10px);
    transition: var(--transition-theme), border-color 0.3s ease;
    animation: fadeInUp 0.8s ease-out;
    box-shadow: 0 4px 24px rgba(0, 0, 0, 0.06);
}

.about-text:hover {
    border-color: var(--color-border-hover);
    background: var(--color-bg-card-hover);
}

.lead {
    font-size: 1.2rem;
    margin-bottom: 1.5rem;
    font-weight: 500;
    line-height: 1.8;
    color: var(--color-heading);
    transition: color 0.35s ease;
}

.about-text p {
    color: var(--color-text-secondary);
    margin-bottom: 1.5rem;
    font-size: 1.05rem;
    line-height: 1.8;
    transition: color 0.35s ease;
}

.about-text a {
    color: var(--color-accent);
    text-decoration: underline;
    font-weight: 500;
}

.about-text a:hover {
    color: var(--color-accent-purple-light);
}

/* ==================== Expertise Cards ==================== */
.expertise-areas {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
    gap: 1.25rem;
    margin-top: var(--spacing-lg);
}

.expertise-item {
    padding: 1.75rem;
    background: var(--color-bg-card);
    border: 1.5px solid var(--color-border);
    border-radius: var(--radius-md);
    transition: var(--transition-theme), transform 0.3s ease, box-shadow 0.3s ease, border-color 0.3s ease;
    backdrop-filter: blur(10px);
    -webkit-backdrop-filter: blur(10px);
    animation: fadeInUp 0.8s ease-out;
}

.expertise-item:hover {
    border-color: var(--color-border-hover);
    transform: translateY(-6px);
    box-shadow: var(--color-shadow-card-hover);
    background: var(--color-bg-card-hover);
}

.expertise-item h3 {
    font-size: 1.15rem;
    margin-bottom: 0.5rem;
    color: var(--color-heading);
}

.expertise-item p {
    color: var(--color-text-secondary);
    font-size: 0.92rem;
    line-height: 1.6;
    transition: color 0.35s ease;
}

/* ==================== Skills Grid ==================== */
.skills-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
    gap: 1.25rem;
    max-width: 1200px;
    margin: 0 auto;
}

.skill-category {
    padding: 1.75rem;
    background: var(--color-bg-card);
    border: 1.5px solid var(--color-border);
    border-radius: var(--radius-md);
    backdrop-filter: blur(10px);
    -webkit-backdrop-filter: blur(10px);
    transition: var(--transition-theme), transform 0.3s ease, box-shadow 0.3s ease, border-color 0.3s ease;
    animation: fadeInUp 0.8s ease-out;
}

.skill-category:hover {
    border-color: var(--color-border-hover);
    box-shadow: var(--color-shadow-skill-hover);
    transform: translateY(-4px);
    background: var(--color-bg-card-hover);
}

.skill-category h3 {
    margin-bottom: 1rem;
    color: var(--color-heading);
    font-size: 1.05rem;
}

.skill-tags {
    display: flex;
    flex-wrap: wrap;
    gap: 0.5rem;
}

.skill-tag {
    padding: 0.4rem 0.9rem;
    background: var(--color-bg-skill-tag);
    border: 1px solid var(--color-accent-purple);
    border-radius: var(--radius);
    color: var(--color-accent);
    font-size: 0.82rem;
    font-weight: 500;
    transition: var(--transition-fast);
    cursor: default;
}

.skill-tag:hover {
    background: var(--color-accent-dim);
    border-color: var(--color-accent);
    box-shadow: var(--color-shadow-skill-tag);
}

/* ==================== Case Studies ==================== */
.case-studies-list {
    max-width: 900px;
    margin: 0 auto 2rem;
    display: grid;
    gap: 2rem;
}

.case-study-card {
    padding: 2.25rem;
    background: var(--color-bg-card);
    border: 1.5px solid var(--color-border);
    border-radius: var(--radius-md);
    backdrop-filter: blur(10px);
    -webkit-backdrop-filter: blur(10px);
    transition: var(--transition-theme), transform 0.3s ease, box-shadow 0.3s ease, border-color 0.3s ease;
    animation: fadeInUp 0.8s ease-out;
    position: relative;
    overflow: hidden;
    box-shadow: 0 2px 12px rgba(0, 0, 0, 0.05);
}

.case-study-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: -100%;
    width: 100%;
    height: 100%;
    background: linear-gradient(90deg, transparent, var(--color-accent-dim), transparent);
    transition: left 0.6s ease;
    pointer-events: none;
}

.case-study-card:hover {
    border-color: var(--color-border-hover);
    transform: translateY(-6px);
    box-shadow: var(--color-shadow-card-hover);
    background: var(--color-bg-card-hover);
}

.case-study-card:hover::before {
    left: 100%;
}

.case-study-header {
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
    margin-bottom: 1.25rem;
    gap: 1rem;
}

.case-study-header h3 {
    font-size: 1.35rem;
    color: var(--color-heading);
    flex: 1;
}

.live-badge {
    display: inline-flex;
    align-items: center;
    gap: 0.3rem;
    padding: 0.3rem 0.75rem;
    background: var(--color-accent-dim);
    border: 1px solid var(--color-border-hover);
    border-radius: var(--radius-sm);
    color: var(--color-accent);
    font-family: var(--font-mono);
    font-size: 0.68rem;
    font-weight: 500;
    text-transform: uppercase;
    letter-spacing: 0.06em;
    white-space: nowrap;
    flex-shrink: 0;
}

.live-badge::before {
    content: '';
    width: 6px;
    height: 6px;
    border-radius: 50%;
    background: var(--color-accent);
    flex-shrink: 0;
}

.case-study-description {
    color: var(--color-text-secondary);
    margin-bottom: 1.5rem;
    font-size: 0.98rem;
    line-height: 1.75;
    transition: color 0.35s ease;
}

.metrics {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(140px, 1fr));
    gap: 1rem;
    margin-bottom: 1.5rem;
    padding: 1.25rem;
    background: var(--color-bg-metrics-panel);
    border-radius: var(--radius);
    border: 1px solid var(--color-border);
    transition: var(--transition-theme);
}

.metric {
    display: flex;
    flex-direction: column;
    gap: 0.3rem;
    text-align: center;
}

.metric-label {
    color: var(--color-text-secondary);
    font-size: 0.78rem;
    text-transform: uppercase;
    letter-spacing: 0.06em;
    font-weight: 600;
    transition: color 0.35s ease;
}

.metric-value {
    color: var(--color-accent);
    font-size: 1.4rem;
    font-weight: 700;
    transition: color 0.35s ease;
}

.tags {
    display: flex;
    flex-wrap: wrap;
    gap: 0.6rem;
    margin-bottom: 1.5rem;
}

.tag {
    display: inline-block;
    padding: 0.35rem 0.8rem;
    background: var(--color-bg-tag);
    border: 1px solid var(--color-border-tag);
    border-radius: var(--radius-lg);
    color: var(--color-accent);
    font-size: 0.78rem;
    font-weight: 500;
    transition: var(--transition-fast);
}

.tag:hover {
    background: var(--color-accent-dim);
    border-color: var(--color-accent);
}

.case-study-links {
    display: flex;
    gap: 1rem;
    flex-wrap: wrap;
    margin-top: 1.5rem;
}

/* ==================== Writing Section ==================== */
.writing-links {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(290px, 1fr));
    gap: 1.25rem;
    max-width: 800px;
    margin: 0 auto;
}

.writing-link {
    display: flex;
    align-items: center;
    padding: 1.75rem;
    background: var(--color-bg-card);
    border: 1.5px solid var(--color-border);
    border-radius: var(--radius-md);
    text-decoration: none;
    transition: var(--transition-theme), transform 0.3s ease, box-shadow 0.3s ease, border-color 0.3s ease;
    backdrop-filter: blur(10px);
    -webkit-backdrop-filter: blur(10px);
    animation: fadeInUp 0.8s ease-out;
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.04);
}

.writing-link:hover {
    border-color: var(--color-border-hover);
    transform: translateY(-5px);
    box-shadow: var(--color-shadow-card-hover);
    background: var(--color-bg-card-hover);
}

.link-icon {
    font-size: 2.25rem;
    min-width: 52px;
    text-align: center;
    flex-shrink: 0;
}

.writing-link h3 {
    color: var(--color-heading);
    margin-bottom: 0.25rem;
    font-size: 1.05rem;
}

.writing-link p {
    color: var(--color-text-secondary);
    font-size: 0.88rem;
    margin: 0;
    line-height: 1.5;
    transition: color 0.35s ease;
}

/* ==================== Contact Section ==================== */
.contact-section {
    background: var(--color-bg-section-alt);
    backdrop-filter: blur(10px);
    -webkit-backdrop-filter: blur(10px);
    transition: var(--transition-theme);
}

.contact-links {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(160px, 1fr));
    gap: 1.25rem;
    max-width: 900px;
    margin: 2rem auto 0;
}

.contact-link {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 0.875rem;
    padding: 1.75rem 1.25rem;
    background: var(--color-bg-card);
    border: 1.5px solid var(--color-border);
    border-radius: var(--radius-md);
    text-decoration: none;
    color: var(--color-heading);
    font-weight: 600;
    font-size: 0.95rem;
    transition: var(--transition-theme), transform 0.3s ease, box-shadow 0.3s ease, border-color 0.3s ease;
    backdrop-filter: blur(10px);
    -webkit-backdrop-filter: blur(10px);
    animation: fadeInUp 0.8s ease-out;
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.04);
}

.contact-link:hover {
    border-color: var(--color-border-hover);
    transform: translateY(-6px);
    box-shadow: var(--color-shadow-contact-hover);
    background: var(--color-bg-card-hover);
    color: var(--color-accent);
}

.contact-icon {
    width: 2rem;
    height: 2rem;
    transition: var(--transition);
    flex-shrink: 0;
}

.contact-link:hover .contact-icon {
    transform: scale(1.15);
}

/* ==================== Footer ==================== */
.footer {
    padding: 1.75rem 2rem;
    text-align: center;
    color: var(--color-text-secondary);
    border-top: 1px solid var(--color-border-footer);
    background: var(--color-bg-footer);
    font-size: 0.9rem;
    transition: var(--transition-theme);
}

/* ==================== Animations ==================== */
@keyframes fadeInDown {
    from { opacity: 0; transform: translateY(-20px); }
    to   { opacity: 1; transform: translateY(0); }
}

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

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

.scroll-animate.visible {
    opacity: 1;
    transform: translateY(0);
}

/* ==================== Utility Classes ==================== */
.text-center { text-align: center; }
.mt-lg { margin-top: var(--spacing-lg); }
.mb-lg { margin-bottom: var(--spacing-lg); }

.text-gradient {
    color: var(--color-accent);
}

/* ==================== Responsive: Tablet ==================== */
@media (max-width: 768px) {
    .nav-menu {
        position: fixed;
        top: 0;
        right: -100%;
        width: min(280px, 80vw);
        height: 100vh;
        background: var(--color-bg-nav);
        border-left: 1.5px solid var(--color-border-nav);
        flex-direction: column;
        justify-content: center;
        gap: 2rem;
        padding: 2rem;
        transition: right 0.35s ease;
        backdrop-filter: blur(24px);
        -webkit-backdrop-filter: blur(24px);
        z-index: 999;
    }

    .nav-menu.active {
        right: 0;
    }

    .nav-menu li::after {
        display: none;
    }

    .nav-link {
        font-size: 1.2rem;
    }

    .mobile-toggle {
        display: flex;
    }

    .hero {
        text-align: center;
        padding: 100px 1.25rem 3rem;
    }

    .hero::before {
        display: none;
    }

    .btn-group {
        justify-content: center;
    }

    .btn {
        width: 100%;
        text-align: center;
    }

    .hero-metrics {
        max-width: 100%;
        justify-content: center;
        padding: 1rem 1.25rem;
        gap: 0;
    }

    .hero-metric-value {
        font-size: 1.35rem;
    }

    .hero-metric-label {
        font-size: 0.65rem;
    }

    section {
        padding: var(--spacing-lg) 1.25rem;
    }

    .expertise-areas,
    .skills-grid,
    .contact-links,
    .writing-links {
        grid-template-columns: 1fr;
    }

    .case-study-header {
        flex-direction: column;
        gap: 0.5rem;
    }

    .case-study-links {
        flex-direction: column;
    }

    .case-study-links .btn {
        width: 100%;
    }

    .metrics {
        grid-template-columns: repeat(3, 1fr);
        gap: 0.75rem;
        padding: 1rem;
    }

    .metric-value {
        font-size: 1.2rem;
    }
}

/* ==================== Responsive: Mobile ==================== */
@media (max-width: 480px) {
    .hero-title {
        font-size: 2rem;
    }

    .hero-description {
        font-size: 1rem;
    }

    .section-title {
        font-size: 1.75rem;
    }

    .nav-container {
        padding: 0.875rem 1rem;
    }

    .logo {
        font-size: 1.3rem;
    }

    .about-text {
        padding: 1.5rem;
    }

    .expertise-item,
    .skill-category,
    .case-study-card,
    .contact-link {
        padding: 1.5rem;
    }

    .hero-metrics {
        flex-wrap: wrap;
        gap: 0.75rem;
    }

    .hero-metric-divider {
        display: none;
    }

    .hero-metric {
        min-width: 80px;
    }

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

    .tags {
        gap: 0.4rem;
    }

    .tag {
        font-size: 0.72rem;
        padding: 0.28rem 0.65rem;
    }
}

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

/* ==================== Recognition ==================== */
.recognition {
    margin-top: var(--spacing-lg);
}

.recognition-heading {
    font-family: var(--font-mono);
    font-size: 0.75rem;
    font-weight: 500;
    text-transform: uppercase;
    letter-spacing: 0.08em;
    color: var(--color-accent);
    margin-bottom: 1rem;
}

.recognition-card {
    max-width: 640px;
    padding: 1.5rem 1.75rem;
    background: var(--color-bg-card);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-md);
    box-shadow: 0 2px 12px rgba(0, 0, 0, 0.05);
    transition: var(--transition-theme);
}

.recognition-card + .recognition-card {
    margin-top: 1.25rem;
}

.recognition-card-top {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 1rem;
    flex-wrap: wrap;
    margin-bottom: 0.85rem;
}

.recognition-eyebrow {
    font-family: var(--font-mono);
    font-size: 0.72rem;
    font-weight: 500;
    text-transform: uppercase;
    letter-spacing: 0.08em;
    color: var(--color-text-secondary);
}

.recognition-title {
    font-size: 1.15rem;
    font-weight: 600;
    color: var(--color-heading);
    margin-bottom: 0.4rem;
}

.recognition-desc {
    font-size: 0.95rem;
    line-height: 1.6;
    color: var(--color-text-secondary);
    margin: 0;
}