/* WebDisk Conference Archive - Main Styles */
:root {
    --color-primary: #1a365d;
    --color-primary-light: #2c5282;
    --color-accent: #b8860b;
    --color-accent-light: #d4a84b;
    --color-neutral: #4a5568;
    --color-neutral-light: #718096;
    --color-bg: #f7fafc;
    --color-bg-alt: #edf2f7;
    --color-white: #fff;
    --font-sans: 'Segoe UI', system-ui, -apple-system, sans-serif;
    --font-serif: Georgia, 'Times New Roman', serif;
    --shadow: 0 2px 8px rgba(0,0,0,0.08);
    --radius: 6px;
}

* {
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
}

body {
    margin: 0;
    font-family: var(--font-sans);
    font-size: 1rem;
    line-height: 1.6;
    color: var(--color-neutral);
    background: var(--color-white);
}

.container {
    max-width: 960px;
    margin: 0 auto;
    padding: 0 1.25rem;
}

/* Header */
.site-header {
    position: sticky;
    top: 0;
    z-index: 100;
    background: var(--color-white);
    box-shadow: var(--shadow);
}

.site-header .container {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding-top: 0.75rem;
    padding-bottom: 0.75rem;
}

.logo img {
    display: block;
    height: 48px;
    width: auto;
}

.main-nav ul {
    list-style: none;
    margin: 0;
    padding: 0;
    display: flex;
    gap: 1.5rem;
}

.main-nav a {
    color: var(--color-primary);
    text-decoration: none;
    font-weight: 500;
}

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

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

.nav-toggle {
    display: none;
    width: 40px;
    height: 40px;
    border: none;
    background: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' fill='none' viewBox='0 0 24 24' stroke='%231a365d'%3E%3Cpath stroke-linecap='round' stroke-linejoin='round' stroke-width='2' d='M4 6h16M4 12h16M4 18h16'/%3E%3C/svg%3E") center/24px no-repeat;
    cursor: pointer;
}

@media (max-width: 768px) {
    .main-nav {
        position: absolute;
        top: 100%;
        left: 0;
        right: 0;
        background: var(--color-white);
        box-shadow: var(--shadow);
        display: none;
    }
    .main-nav.is-open { display: block; }
    .main-nav ul { flex-direction: column; padding: 1rem; gap: 0.5rem; }
    .nav-toggle { display: block; }
}

/* Hero */
.hero {
    position: relative;
    min-height: 420px;
    display: flex;
    align-items: center;
    justify-content: center;
    overflow: hidden;
}

.hero-banner {
    position: absolute;
    inset: 0;
}

.hero-banner img {
    width: 100%;
    height: 100%;
    object-fit: cover;
}

.hero-overlay {
    position: relative;
    z-index: 2;
    width: 100%;
    padding: 3rem 0;
    background: linear-gradient(to bottom, rgba(26,54,93,0.75), rgba(26,54,93,0.9));
    color: var(--color-white);
    text-align: center;
}

.hero h1 {
    margin: 0 0 0.75rem;
    font-size: clamp(1.75rem, 4vw, 2.5rem);
    font-weight: 700;
}

.hero-lead {
    margin: 0 auto 1.5rem;
    max-width: 640px;
    font-size: 1.1rem;
    opacity: 0.95;
}

.hero-cta {
    display: flex;
    flex-wrap: wrap;
    gap: 0.75rem;
    justify-content: center;
}

.btn {
    display: inline-block;
    padding: 0.6rem 1.25rem;
    border-radius: var(--radius);
    font-weight: 600;
    text-decoration: none;
    transition: opacity 0.2s;
}

.btn:hover { opacity: 0.9; }

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

.btn-secondary {
    background: transparent;
    color: var(--color-white);
    border: 2px solid var(--color-white);
}

/* Sections */
.section {
    padding: 3rem 0;
}

.section-alt {
    background: var(--color-bg-alt);
}

.section h2 {
    margin: 0 0 1.25rem;
    font-size: 1.75rem;
    color: var(--color-primary);
    font-weight: 700;
}

.content-block p {
    margin: 0 0 1rem;
}

.content-block a {
    color: var(--color-primary-light);
    text-decoration: underline;
}

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

.link-grid {
    list-style: none;
    margin: 1.5rem 0 0;
    padding: 0;
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(180px, 1fr));
    gap: 0.5rem;
}

.link-grid a {
    display: block;
    padding: 0.5rem 0.75rem;
    background: var(--color-white);
    border-radius: var(--radius);
    text-decoration: none;
    color: var(--color-primary);
    border: 1px solid #e2e8f0;
}

.link-grid a:hover {
    border-color: var(--color-accent);
    background: #fefce8;
}

/* Subpage banner */
.page-banner {
    margin-bottom: 2rem;
    border-radius: var(--radius);
    overflow: hidden;
    box-shadow: var(--shadow);
}

.page-banner img {
    width: 100%;
    height: auto;
    max-height: 320px;
    object-fit: cover;
    display: block;
}

/* Footer */
.site-footer {
    padding: 2rem 0;
    background: var(--color-primary);
    color: var(--color-white);
    text-align: center;
}

.footer-nav {
    display: flex;
    flex-wrap: wrap;
    gap: 1rem;
    justify-content: center;
    margin-bottom: 1rem;
}

.footer-nav a {
    color: rgba(255,255,255,0.9);
    text-decoration: none;
}

.footer-nav a:hover {
    color: var(--color-accent-light);
}

.copyright {
    margin: 0;
    font-size: 0.9rem;
    opacity: 0.85;
}

/* Breadcrumb */
.breadcrumb {
    padding: 0.75rem 0;
    font-size: 0.9rem;
}

.breadcrumb a {
    color: var(--color-primary-light);
    text-decoration: none;
}

.breadcrumb a:hover { text-decoration: underline; }

.breadcrumb span { color: var(--color-neutral-light); }