/* Google Fonts - Inter */
@import url('https://fonts.googleapis.com/css2?family=Inter:wght@300;400;500;600;700&display=swap');

/* --- CSS Variables: Deep Navy + Sky Blue (differentiated from CHI orange scheme) --- */
:root {
    --primary-dark: #0F2B4A;   /* Deep Navy - authoritative, technical */
    --primary-light: #EFF6FF;  /* Blue 50 - clean light background */
    --accent-color: #0284C7;   /* Sky Blue 600 - trust/technology signaling */
    --accent-hover: #0369A1;   /* Sky Blue 700 - hover state */
    --text-main: #334155;      /* Slate 700 - readable text */
    --text-light: #94A3B8;     /* Slate 400 - muted text */
    --white: #ffffff;
    --border-color: #E2E8F0;
}

/* --- Global Resets & Typography --- */
* {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

body {
    font-family: 'Inter', sans-serif;
    line-height: 1.6;
    color: var(--text-main);
    background-color: var(--white);
    scroll-behavior: smooth;
}

a {
    color: var(--accent-color);
    text-decoration: none;
    font-weight: 600;
    transition: color 0.2s ease;
}

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

h1, h2, h3 {
    color: var(--primary-dark);
    line-height: 1.2;
}

section {
    padding: 4rem 1.5rem;
    max-width: 1000px;
    margin: 0 auto;
    border-bottom: 1px solid var(--border-color);
}

/* --- Sticky Navigation --- */
nav {
    position: sticky;
    top: 0;
    background-color: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    border-bottom: 1px solid var(--border-color);
    z-index: 1000;
    padding: 1rem 0;
}

.nav-container {
    max-width: 1000px;
    margin: 0 auto;
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 0 1.5rem;
}

.nav-logo {
    font-weight: 700;
    font-size: 1.05rem;
    color: var(--primary-dark);
}

.nav-links {
    display: flex;
    gap: 1.5rem;
}

.nav-links a {
    color: var(--text-main);
    font-size: 0.95rem;
    font-weight: 500;
}

.nav-links a:hover {
    color: var(--accent-color);
    text-decoration: none;
}

@media (max-width: 768px) {
    .nav-links {
        display: none;
    }
    .nav-logo {
        font-size: 0.95rem;
    }
}

/* --- Hero Section (no background image - gradient only) --- */
#home {
    position: relative;
    background: linear-gradient(135deg, #0F2B4A 0%, #173A5E 50%, #0C1F38 100%);
    color: var(--white);
    padding: 6rem 1.5rem;
    text-align: center;
    border-bottom: none;
    overflow: hidden;
}

/* Subtle ambient glow effect replacing the background image */
#home::before {
    content: '';
    position: absolute;
    top: 0; left: 0; right: 0; bottom: 0;
    background-image:
        radial-gradient(circle at 15% 85%, rgba(2, 132, 199, 0.18) 0%, transparent 55%),
        radial-gradient(circle at 85% 15%, rgba(2, 132, 199, 0.12) 0%, transparent 50%),
        radial-gradient(circle at 50% 50%, rgba(2, 132, 199, 0.06) 0%, transparent 70%);
    z-index: 0;
}

#home > * {
    position: relative;
    z-index: 1;
}

.hero-label {
    background-color: var(--accent-color);
    color: var(--white);
    padding: 0.25rem 0.75rem;
    border-radius: 4px;
    font-size: 0.8rem;
    text-transform: uppercase;
    letter-spacing: 1px;
    font-weight: 700;
    display: inline-block;
    margin-bottom: 1rem;
}

.hero-title {
    font-size: 2.4rem;
    font-weight: 700;
    color: var(--white);
    margin-bottom: 1rem;
    max-width: 820px;
    margin-left: auto;
    margin-right: auto;
}

.hero-subtitle {
    font-size: 1.2rem;
    font-weight: 300;
    color: #BAE6FD;
    margin-bottom: 2rem;
    max-width: 680px;
    margin-left: auto;
    margin-right: auto;
}

.hero-meta {
    display: flex;
    justify-content: center;
    gap: 2rem;
    font-size: 1rem;
    color: #E0F2FE;
    margin-bottom: 3rem;
    flex-wrap: wrap;
}

.cta-button {
    display: inline-block;
    background-color: var(--accent-color);
    color: var(--white);
    padding: 0.75rem 2rem;
    border-radius: 6px;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.5px;
    border: 2px solid transparent;
    transition: all 0.3s ease;
}

.cta-button:hover {
    background-color: transparent;
    border-color: var(--accent-color);
    color: var(--accent-color);
    text-decoration: none;
}

/* --- About / Motivation --- */
.shifts-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 2rem;
    margin-top: 3rem;
}

.shift-card {
    background-color: var(--primary-light);
    padding: 2rem;
    border-radius: 8px;
    border-left: 4px solid var(--accent-color);
    transition: transform 0.2s ease;
    display: flex;
    flex-direction: column;
}

.shift-card:hover {
    transform: translateY(-2px);
}

.shift-card h3 {
    margin-bottom: 0.5rem;
    font-size: 1.1rem;
}

.shift-label {
    font-size: 0.75rem;
    text-transform: uppercase;
    color: var(--text-light);
    margin-bottom: 0.5rem;
    display: block;
    font-weight: 700;
}

/* --- Thematic Focus Block --- */
.themes-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 1.5rem;
    margin-top: 2rem;
}

.theme-card {
    background-color: var(--primary-dark);
    color: var(--white);
    padding: 1.75rem;
    border-radius: 8px;
    border-top: 4px solid var(--accent-color);
}

.theme-card h3 {
    color: #BAE6FD;
    margin-bottom: 0.75rem;
    font-size: 1rem;
}

.theme-card p {
    font-size: 0.9rem;
    color: #CBD5E1;
    line-height: 1.6;
}

/* --- Call for Participation --- */
.submission-box {
    background-color: #EFF6FF;
    border: 1px solid #BFDBFE;
    border-radius: 8px;
    padding: 2rem;
    margin-top: 2rem;
}

.submission-box h3 {
    margin-bottom: 1rem;
}

.dates-list {
    list-style: none;
    margin-top: 1rem;
}

.dates-list li {
    display: flex;
    justify-content: space-between;
    padding: 0.75rem 0;
    border-bottom: 1px solid rgba(0,0,0,0.05);
    gap: 1rem;
}

.dates-list li:last-child {
    border-bottom: none;
}

.dates-list li strong {
    color: var(--primary-dark);
}

/* --- Organizers --- */
.organizers-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(180px, 1fr));
    gap: 2rem;
    margin-top: 2rem;
}

.organizer-card {
    text-align: center;
}

.organizer-photo {
    width: 140px;
    height: 140px;
    object-fit: cover;
    border-radius: 50%;
    display: block;
    margin: 0 auto 1rem auto;
    border: 3px solid var(--primary-light);
    box-shadow: 0 4px 6px rgba(0,0,0,0.1);
}

.organizer-photo-placeholder {
    width: 140px;
    height: 140px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    background-color: var(--primary-light);
    border: 3px solid var(--border-color);
    margin: 0 auto 1rem auto;
    font-size: 2.5rem;
    color: var(--text-light);
}

.organizer-card h3 {
    font-size: 1rem;
    margin-bottom: 0.25rem;
    color: var(--primary-dark);
}

.organizer-card p {
    font-size: 0.85rem;
    color: var(--text-light);
}

/* --- Registration call-out banner --- */
.register-banner {
    background-color: var(--primary-dark);
    color: var(--white);
    text-align: center;
    padding: 3rem 1.5rem;
    border-bottom: none;
    max-width: 100%;
}

.register-banner h2 {
    color: #BAE6FD;
    margin-bottom: 1rem;
}

.register-banner p {
    color: #CBD5E1;
    margin-bottom: 2rem;
    font-size: 1rem;
}

/* --- Registration Form Page --- */
.form-container {
    max-width: 640px;
    margin: 0 auto;
    padding: 2rem 1.5rem;
}

.form-group {
    margin-bottom: 1.5rem;
}

.form-group label {
    display: block;
    font-weight: 600;
    font-size: 0.9rem;
    color: var(--primary-dark);
    margin-bottom: 0.4rem;
}

.form-group input,
.form-group select,
.form-group textarea {
    width: 100%;
    padding: 0.6rem 0.9rem;
    border: 1px solid var(--border-color);
    border-radius: 6px;
    font-size: 0.95rem;
    font-family: 'Inter', sans-serif;
    color: var(--text-main);
    transition: border-color 0.2s ease;
}

.form-group input:focus,
.form-group select:focus,
.form-group textarea:focus {
    outline: none;
    border-color: var(--accent-color);
    box-shadow: 0 0 0 3px rgba(2, 132, 199, 0.1);
}

.form-group textarea {
    resize: vertical;
    min-height: 80px;
}

.submit-btn {
    background-color: var(--accent-color);
    color: var(--white);
    border: none;
    padding: 0.75rem 2rem;
    border-radius: 6px;
    font-size: 1rem;
    font-weight: 600;
    font-family: 'Inter', sans-serif;
    cursor: pointer;
    transition: background-color 0.2s ease;
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.submit-btn:hover {
    background-color: var(--accent-hover);
}

.form-note {
    font-size: 0.85rem;
    color: var(--text-light);
    margin-top: 0.4rem;
}

/* --- Footer --- */
footer {
    background-color: var(--primary-dark);
    color: var(--text-light);
    text-align: center;
    padding: 3rem 1.5rem;
    font-size: 0.9rem;
}

footer p {
    margin-bottom: 0.5rem;
}

footer a {
    color: #7DD3FC;
}