/* ============================================
   HASSAIRI.COM — Design System
   ============================================ */

:root {
    --bg: #0a0a0a;
    --bg-elevated: #111111;
    --text: #e8e6e3;
    --text-muted: #8a8a8a;
    --text-dim: #5a5a5a;
    --accent: #c9a96e;
    --accent-dim: rgba(201, 169, 110, 0.15);
    --border: #1e1e1e;
    --font-body: 'Inter', -apple-system, sans-serif;
    --font-display: 'Playfair Display', Georgia, serif;
    --max-width: 1100px;
    --space-xs: 0.5rem;
    --space-sm: 1rem;
    --space-md: 2rem;
    --space-lg: 4rem;
    --space-xl: 8rem;
}

/* ============================================
   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;
}

body {
    font-family: var(--font-body);
    font-weight: 300;
    font-size: 1rem;
    line-height: 1.7;
    color: var(--text);
    background-color: var(--bg);
}

a {
    color: var(--accent);
    text-decoration: none;
    transition: opacity 0.2s ease;
}

a:hover {
    opacity: 0.7;
}

strong {
    font-weight: 500;
    color: #fff;
}

em {
    font-style: italic;
    color: var(--text);
}

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

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

/* ============================================
   Navigation
   ============================================ */

.nav {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 100;
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1.5rem var(--space-md);
    transition: all 0.3s ease;
}

.nav.scrolled {
    background: rgba(10, 10, 10, 0.9);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    padding: 1rem var(--space-md);
    border-bottom: 1px solid var(--border);
}

.nav-name {
    font-family: var(--font-display);
    font-size: 1.25rem;
    color: #fff;
    letter-spacing: 0.02em;
}

.nav-links {
    display: flex;
    gap: 2.5rem;
}

.nav-links a {
    font-size: 0.8rem;
    font-weight: 400;
    letter-spacing: 0.08em;
    text-transform: uppercase;
    color: var(--text-muted);
    transition: color 0.2s ease;
}

.nav-links a:hover {
    color: #fff;
    opacity: 1;
}

/* ============================================
   Hero
   ============================================ */

.hero {
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    text-align: center;
    padding: var(--space-xl) var(--space-md);
    position: relative;
}

.hero::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 50%;
    transform: translateX(-50%);
    width: 1px;
    height: 80px;
    background: linear-gradient(to bottom, transparent, var(--text-dim));
    animation: fadeInDown 1.5s ease 1s both;
}

.hero-inner {
    animation: fadeIn 1s ease both;
}

.hero-name {
    font-family: var(--font-display);
    font-size: clamp(3rem, 8vw, 6.5rem);
    font-weight: 400;
    letter-spacing: -0.02em;
    line-height: 1.05;
    color: #fff;
    margin-bottom: var(--space-sm);
}

.hero-tagline {
    font-size: 0.85rem;
    font-weight: 400;
    letter-spacing: 0.2em;
    text-transform: uppercase;
    color: var(--text-muted);
    margin-bottom: var(--space-md);
}

.hero-line {
    width: 60px;
    height: 1px;
    background: var(--accent);
    margin: 0 auto var(--space-md);
}

.hero-sub {
    font-family: var(--font-display);
    font-size: clamp(1.1rem, 2vw, 1.35rem);
    font-weight: 400;
    font-style: italic;
    color: var(--text-muted);
    line-height: 1.8;
    max-width: 520px;
    margin: 0 auto;
}

/* ============================================
   Sections (shared)
   ============================================ */

.section {
    padding: var(--space-xl) 0;
    border-top: 1px solid var(--border);
    opacity: 0;
    transform: translateY(30px);
    transition: opacity 0.8s ease, transform 0.8s ease;
}

.section.visible {
    opacity: 1;
    transform: translateY(0);
}

.section-label {
    font-size: 0.7rem;
    font-weight: 500;
    letter-spacing: 0.2em;
    text-transform: uppercase;
    color: var(--accent);
    margin-bottom: var(--space-lg);
}

/* ============================================
   About
   ============================================ */

.about-grid {
    display: grid;
    grid-template-columns: 1fr 300px;
    gap: var(--space-xl);
    align-items: start;
}

.about-lede {
    font-family: var(--font-display);
    font-size: 1.4rem;
    font-weight: 400;
    line-height: 1.6;
    color: #fff;
    margin-bottom: var(--space-md);
}

.about-main p {
    margin-bottom: var(--space-sm);
    color: var(--text-muted);
}

.about-main p:last-child {
    margin-bottom: 0;
}

.about-aside {
    display: flex;
    flex-direction: column;
    gap: var(--space-md);
    padding-top: 0.25rem;
}

.credential {
    display: flex;
    flex-direction: column;
    gap: 0.35rem;
    padding-bottom: var(--space-md);
    border-bottom: 1px solid var(--border);
}

.credential:last-child {
    border-bottom: none;
    padding-bottom: 0;
}

.credential-label {
    font-size: 0.65rem;
    font-weight: 500;
    letter-spacing: 0.15em;
    text-transform: uppercase;
    color: var(--text-dim);
}

.credential-value {
    font-size: 0.95rem;
    font-weight: 400;
    color: var(--text);
    line-height: 1.5;
}

/* ============================================
   Path
   ============================================ */

.path-items {
    display: flex;
    flex-direction: column;
    gap: 0;
}

.path-item {
    display: grid;
    grid-template-columns: 140px 260px 1fr;
    gap: var(--space-md);
    padding: 1.25rem 0;
    border-bottom: 1px solid var(--border);
    align-items: baseline;
}

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

.path-year {
    font-size: 0.8rem;
    font-weight: 400;
    color: var(--text-dim);
    font-variant-numeric: tabular-nums;
}

.path-place {
    font-weight: 500;
    color: #fff;
    font-size: 0.95rem;
}

.path-desc {
    font-size: 0.9rem;
    color: var(--text-muted);
}

/* ============================================
   Research
   ============================================ */

.papers {
    display: flex;
    flex-direction: column;
    gap: 0;
}

.paper {
    display: grid;
    grid-template-columns: 80px 1fr;
    gap: var(--space-md);
    padding: var(--space-md) 0;
    border-bottom: 1px solid var(--border);
    transition: background 0.2s ease;
}

.paper:first-child {
    padding-top: 0;
}

.paper:last-child {
    border-bottom: none;
}

.paper-year {
    font-size: 0.8rem;
    font-weight: 400;
    color: var(--text-dim);
    padding-top: 0.2rem;
    font-variant-numeric: tabular-nums;
}

.paper-title {
    font-family: var(--font-display);
    font-size: 1.15rem;
    font-weight: 400;
    color: #fff;
    line-height: 1.45;
    margin-bottom: 0.5rem;
}

.paper-journal {
    font-size: 0.85rem;
    font-style: italic;
    color: var(--accent);
    margin-bottom: 0.3rem;
}

.paper-authors {
    font-size: 0.8rem;
    color: var(--text-dim);
}

.papers-note {
    margin-top: var(--space-md);
    font-size: 0.8rem;
    color: var(--text-dim);
}

/* ============================================
   Methods
   ============================================ */

.methods-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: var(--space-md);
}

.method-group {
    padding: var(--space-md);
    border: 1px solid var(--border);
    border-radius: 2px;
    transition: border-color 0.3s ease;
}

.method-group:hover {
    border-color: var(--accent);
}

.method-group h4 {
    font-size: 0.7rem;
    font-weight: 500;
    letter-spacing: 0.15em;
    text-transform: uppercase;
    color: #fff;
    margin-bottom: 0.75rem;
}

.method-group p {
    font-size: 0.85rem;
    color: var(--text-muted);
    line-height: 1.6;
}

/* ============================================
   Contact
   ============================================ */

.contact {
    border-top: 1px solid var(--border);
    text-align: center;
}

.contact-inner {
    max-width: 550px;
    margin: 0 auto;
}

.contact-heading {
    font-family: var(--font-display);
    font-size: clamp(2.5rem, 5vw, 4rem);
    font-weight: 400;
    color: #fff;
    margin-bottom: var(--space-sm);
}

.contact-sub {
    font-size: 0.95rem;
    color: var(--text-muted);
    margin-bottom: var(--space-lg);
    line-height: 1.7;
}

.contact-links {
    display: flex;
    justify-content: center;
    gap: var(--space-md);
}

.contact-link {
    font-size: 0.8rem;
    font-weight: 400;
    letter-spacing: 0.1em;
    text-transform: uppercase;
    color: var(--text-muted);
    padding: 0.75rem 1.5rem;
    border: 1px solid var(--border);
    border-radius: 2px;
    transition: all 0.3s ease;
}

.contact-link:hover {
    border-color: var(--accent);
    color: var(--accent);
    opacity: 1;
}

/* ============================================
   Footer
   ============================================ */

.footer {
    padding: var(--space-md) 0;
    border-top: 1px solid var(--border);
}

.footer .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    font-size: 0.75rem;
    color: var(--text-dim);
}

/* ============================================
   Animations
   ============================================ */

@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

@keyframes fadeInDown {
    from {
        opacity: 0;
    }
    to {
        opacity: 1;
    }
}

/* ============================================
   Responsive
   ============================================ */

@media (max-width: 900px) {
    .about-grid {
        grid-template-columns: 1fr;
        gap: var(--space-lg);
    }

    .about-aside {
        display: grid;
        grid-template-columns: 1fr 1fr;
        gap: var(--space-md);
    }

    .path-item {
        grid-template-columns: 100px 1fr;
        gap: var(--space-sm);
    }

    .path-desc {
        grid-column: 2;
    }

    .methods-grid {
        grid-template-columns: repeat(2, 1fr);
    }
}

@media (max-width: 600px) {
    :root {
        --space-xl: 5rem;
    }

    .nav-links {
        gap: 1.5rem;
    }

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

    .path-item {
        grid-template-columns: 1fr;
        gap: 0.25rem;
        padding: 1rem 0;
    }

    .path-year {
        font-size: 0.7rem;
    }

    .paper {
        grid-template-columns: 1fr;
        gap: 0.5rem;
    }

    .paper-year {
        font-size: 0.7rem;
        letter-spacing: 0.1em;
    }

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

    .contact-links {
        flex-direction: column;
        align-items: center;
    }

    .contact-link {
        width: 100%;
        max-width: 200px;
        text-align: center;
    }
}