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

:root {
    --color: #CD7F32;
    --hover: #DA8A67;
    --white: #FFFFFF;
    --black: #1A1A1A;
    --dark-gray: #4A4A4A;
    --light-gray: #E5E7EB;
    --shadow: 0 4px 12px rgba(0, 0, 0, 0.08);
    --transition: all 0.3s ease;
}

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

body {
    font-family: 'Inter', sans-serif;
    line-height: 1.7;
    color: var(--dark-gray);
    background: var(--white);
}

/* Header */
header {
    background: var(--glass);
    backdrop-filter: blur(4px);
    padding: 1.5rem 2rem;
    display: flex;
    align-items: center;
    justify-content: space-between;
    position: sticky;
    top: 0;
    z-index: 1000;
    box-shadow: var(--shadow);
}

.logo {
    height: 60px;
    transition: var(--transition);
}

.logo:hover {
    transform: scale(1.05);
}

nav ul {
    list-style: none;
    display: flex;
    gap: 1.5rem;
}

nav a {
    color: var(--dark-gray);
    font-weight: 500;
    font-size: 1rem;
    text-decoration: none;
    position: relative;
    transition: var(--transition);
}

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

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

nav a:hover::after {
    width: 100%;
}

/* Cover Section */
.cover {
    position: relative;
    min-height: 500px;
    display: flex;
    align-items: center;
    justify-content: center;
    background-color: var(--black);
    padding: 4rem 2rem;
    overflow: hidden;
}

.cover::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background-image: url('../img/pi-day-2025/s0.JPG');
    background-size: cover;
    background-position: center;
    opacity: 0.4;
    z-index: 1;
}

.cover__inner {
    position: relative;
    z-index: 2;
    text-align: center;
    max-width: 800px;
}

.cover h1 {
    color: var(--white);
    font-size: 3.5rem;
    font-weight: 700;
    margin-bottom: 1.5rem;
}

.cover p {
    color: var(--white);
    font-size: 1.25rem;
    margin-bottom: 2rem;
}

/* Button Styles */
.button {
    display: inline-block;
    text-decoration: none;
    background: var(--color);
    color: var(--black);
    padding: 0.8rem 2rem;
    border-radius: 8px;
    font-weight: 600;
    font-size: 1rem;
    transition: var(--transition);
}

.button:hover {
    background: var(--hover);
    transform: translateY(-2px);
}

.button.secondary {
    background: var(--dark-gray);
    color: var(--white);
}

.button.secondary:hover {
    background: #5a5a5a;
}

/* Spacer */
.spacer {
    height: 4rem;
}

/* Group Section */
.group {
    max-width: 1200px;
    margin: 0 auto;
    padding: 2rem 1.5rem;
}

.group h2 {
    font-size: 2.5rem;
    font-weight: 700;
    color: var(--black);
    text-align: center;
    margin-bottom: 1rem;
}

.group p {
    font-size: 1.1rem;
    text-align: center;
    margin-bottom: 1.5rem;
}

/* Resource Cards */
.resource-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
    margin-top: 2rem;
}

.resource-card {
    background: var(--white);
    border: 1px solid var(--light-gray);
    border-radius: 12px;
    padding: 2rem;
    text-align: center;
    transition: var(--transition);
    box-shadow: var(--shadow);
}

.resource-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 6px 20px rgba(0, 0, 0, 0.1);
}

.resource-card h3 {
    font-size: 1.6rem;
    font-weight: 600;
    color: var(--black);
    margin-bottom: 0.75rem;
}

.resource-card p {
    font-size: 1rem;
    margin-bottom: 1.5rem;
}

.resource-icon {
    font-size: 2.5rem;
    color: var(--color);
    margin-bottom: 1rem;
}

.resource-card .button {
    margin: 0.5rem;
}

/* Combined Columns */
.combined-columns {
    display: flex;
    gap: 2rem;
    flex-wrap: wrap;
    justify-content: center;
}

.column {
    flex: 1;
    min-width: 280px;
    text-align: center;
}

.column ul {
    list-style: none;
    text-align: left;
    margin: 1rem auto;
    max-width: 300px;
}

.column li {
    font-size: 0.95rem;
    margin-bottom: 0.5rem;
    position: relative;
    padding-left: 1.5rem;
}

.column li::before {
    content: '✓';
    position: absolute;
    left: 0;
    color: var(--color);
}

/* Book List Section */
.book-list {
    margin-top: 2rem;
}

.book-table {
    width: 100%;
    border-collapse: collapse;
    background: var(--white);
    border-radius: 12px;
    overflow: hidden;
    box-shadow: var(--shadow);
}

.book-table th,
.book-table td {
    padding: 1rem;
    text-align: left;
    border-bottom: 1px solid var(--light-gray);
}

.book-table th {
    background: var(--color);
    color: var(--black);
    font-weight: 600;
}

.book-table tr:last-child td {
    border-bottom: none;
}

.book-table tr:hover {
    background: var(--light-gray);
}

/* Form Container */
.form-container {
    max-width: 800px;
    margin: 2rem auto;
    padding: 1.5rem;
    background: var(--white);
    border-radius: 12px;
    box-shadow: var(--shadow);
}

.form-container iframe {
    width: 100%;
    border: none;
    border-radius: 8px;
    min-height: 1200px;
}

/* Animations */
@keyframes fadeIn {
    from { opacity: 0; transform: translateY(10px); }
    to { opacity: 1; transform: translateY(0); }
}

.resource-card, .book-table, .form-container {
    animation: fadeIn 0.5s ease forwards;
}

/* Responsive Design */
@media (max-width: 768px) {
    .cover h1 {
        font-size: 2.2rem;
    }

    .cover p {
        font-size: 1rem;
    }

    .group h2 {
        font-size: 2rem;
    }

    .group p {
        font-size: 1rem;
    }

    .resource-card h3 {
        font-size: 1.4rem;
    }

    .combined-columns {
        flex-direction: column;
        gap: 1.5rem;
    }

    .form-container iframe {
        min-height: 1000px;
    }

    .book-table th,
    .book-table td {
        font-size: 0.9rem;
        padding: 0.75rem;
    }

    header {
        flex-direction: column;
        gap: 1rem;
    }

    nav ul {
        flex-wrap: wrap;
        justify-content: center;
    }
}

@media (max-width: 480px) {
    .cover {
        padding: 2rem 1rem;
    }

    .cover h1 {
        font-size: 1.8rem;
    }

    .button {
        padding: 0.6rem 1.5rem;
        font-size: 0.9rem;
    }

    .spacer {
        height: 2rem;
    }
}