:root {
    --primary-color: #2563eb;
    --primary-hover: #1d4ed8;
    --secondary-color: #64748b;
    --background-color: #f8fafc;
    --surface-color: #ffffff;
    --text-primary: #1e293b;
    --text-secondary: #475569;
    --border-color: #e2e8f0;
    --success-color: #10b981;
    --warning-color: #f59e0b;
    --danger-color: #ef4444;
    --shadow-sm: 0 1px 2px 0 rgb(0 0 0 / 0.05);
    --shadow-md: 0 4px 6px -1px rgb(0 0 0 / 0.1), 0 2px 4px -2px rgb(0 0 0 / 0.1);
    --shadow-lg: 0 10px 15px -3px rgb(0 0 0 / 0.1), 0 4px 6px -4px rgb(0 0 0 / 0.1);
    --radius-md: 0.5rem;
    --radius-lg: 0.75rem;
    --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
}

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

body {
    font-family: var(--font-sans);
    background-color: var(--background-color);
    color: var(--text-primary);
    line-height: 1.5;
    -webkit-font-smoothing: antialiased;
}

a {
    text-decoration: none;
    color: inherit;
}

/* Layout */
.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 1.5rem;
}

/* Header */
header {
    background-color: var(--surface-color);
    border-bottom: 1px solid var(--border-color);
    position: sticky;
    top: 0;
    z-index: 50;
    box-shadow: var(--shadow-sm);
}

.header-content {
    display: flex;
    justify-content: space-between;
    align-items: center;
    height: 4rem;
}

.logo {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--primary-color);
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

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

.nav-link {
    color: var(--text-secondary);
    font-weight: 500;
    transition: color 0.2s;
}

.nav-link:hover {
    color: var(--primary-color);
}

/* Hero Section */
.hero {
    padding: 4rem 0;
    text-align: center;
    background: linear-gradient(to bottom, var(--surface-color), var(--background-color));
}

.hero h1 {
    font-size: 2.5rem;
    font-weight: 800;
    margin-bottom: 1rem;
    letter-spacing: -0.025em;
}

.hero p {
    color: var(--text-secondary);
    font-size: 1.125rem;
    max-width: 600px;
    margin: 0 auto 2rem;
}

/* Search & Filter */
.search-section {
    background-color: var(--surface-color);
    padding: 1.5rem;
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-md);
    margin-bottom: 2rem;
    display: flex;
    gap: 1rem;
    flex-wrap: wrap;
    align-items: center;
}

.search-input {
    flex: 1;
    min-width: 300px;
    padding: 0.75rem 1rem;
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    font-size: 1rem;
    transition: border-color 0.2s, box-shadow 0.2s;
}

.search-input:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.1);
}

.filter-select {
    padding: 0.75rem 2rem 0.75rem 1rem;
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    background-color: var(--surface-color);
    font-size: 0.875rem;
    cursor: pointer;
}

.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 0.75rem 1.5rem;
    border-radius: var(--radius-md);
    font-weight: 600;
    transition: all 0.2s;
    cursor: pointer;
    border: none;
}

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

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

/* Grid */
.grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(350px, 1fr));
    gap: 1.5rem;
    margin-bottom: 4rem;
}

/* Card */
.card {
    background-color: var(--surface-color);
    border-radius: var(--radius-lg);
    border: 1px solid var(--border-color);
    overflow: hidden;
    transition: transform 0.2s, box-shadow 0.2s;
    display: flex;
    flex-direction: column;
}

.card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-lg);
}

.card-header {
    padding: 1.5rem;
    border-bottom: 1px solid var(--border-color);
}

.badge {
    display: inline-block;
    padding: 0.25rem 0.75rem;
    border-radius: 9999px;
    font-size: 0.75rem;
    font-weight: 600;
    text-transform: uppercase;
    margin-bottom: 0.5rem;
}

.badge-blue {
    background-color: #eff6ff;
    color: #1d4ed8;
}

.badge-green {
    background-color: #ecfdf5;
    color: #047857;
}

.card-title {
    font-size: 1.125rem;
    font-weight: 700;
    line-height: 1.4;
    margin-bottom: 0.5rem;
    display: -webkit-box;
    -webkit-line-clamp: 2;
    line-clamp: 2;
    -webkit-box-orient: vertical;
    overflow: hidden;
}

.card-meta {
    display: flex;
    align-items: center;
    gap: 1rem;
    font-size: 0.875rem;
    color: var(--text-secondary);
}

.card-body {
    padding: 1.5rem;
    flex: 1;
}

.info-row {
    display: flex;
    justify-content: space-between;
    margin-bottom: 0.75rem;
    font-size: 0.875rem;
}

.info-label {
    color: var(--text-secondary);
}

.info-value {
    font-weight: 500;
    color: var(--text-primary);
}

.card-footer {
    padding: 1rem 1.5rem;
    background-color: #f8fafc;
    border-top: 1px solid var(--border-color);
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.deadline {
    font-size: 0.875rem;
    color: var(--danger-color);
    font-weight: 600;
}

/* Detail Page */
.detail-header {
    background-color: var(--surface-color);
    padding: 3rem 0;
    border-bottom: 1px solid var(--border-color);
    margin-bottom: 2rem;
}

.detail-title {
    font-size: 2rem;
    font-weight: 800;
    margin-bottom: 1.5rem;
    line-height: 1.3;
}

.detail-meta {
    display: flex;
    gap: 2rem;
    color: var(--text-secondary);
    font-size: 1rem;
}

.detail-content {
    background-color: var(--surface-color);
    border-radius: var(--radius-lg);
    padding: 2rem;
    box-shadow: var(--shadow-sm);
    border: 1px solid var(--border-color);
}

.section-title {
    font-size: 1.25rem;
    font-weight: 700;
    margin-bottom: 1rem;
    padding-bottom: 0.5rem;
    border-bottom: 2px solid var(--border-color);
    color: var(--text-primary);
}

.detail-row {
    margin-bottom: 2rem;
}

.detail-text {
    color: var(--text-secondary);
    line-height: 1.7;
    white-space: pre-line;
}

.tag-list {
    display: flex;
    flex-wrap: wrap;
    gap: 0.5rem;
    margin-top: 1rem;
}

.tag {
    background-color: #f1f5f9;
    color: var(--text-secondary);
    padding: 0.25rem 0.75rem;
    border-radius: 0.25rem;
    font-size: 0.875rem;
}

/* Footer */
footer {
    background-color: var(--surface-color);
    border-top: 1px solid var(--border-color);
    padding: 3rem 0;
    margin-top: auto;
}

.footer-content {
    text-align: center;
    color: var(--text-secondary);
}

/* Authentication Forms */
.auth-wrapper {
    min-height: calc(100vh - 4rem - 200px);
    /* Adjust based on header/footer */
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 2rem 0;
}

.auth-container {
    width: 100%;
    max-width: 420px;
    background-color: var(--surface-color);
    padding: 2.5rem;
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-lg);
    border: 1px solid var(--border-color);
}

.auth-header {
    text-align: center;
    margin-bottom: 2.5rem;
}

.auth-header h1 {
    font-size: 1.75rem;
    color: var(--text-primary);
    margin-bottom: 0.5rem;
}

.auth-header p {
    color: var(--text-secondary);
    font-size: 0.95rem;
}

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

.form-label {
    display: block;
    margin-bottom: 0.5rem;
    font-weight: 500;
    color: var(--text-primary);
    font-size: 0.95rem;
}

.input-group {
    position: relative;
}

.input-icon {
    position: absolute;
    left: 1rem;
    top: 50%;
    transform: translateY(-50%);
    color: var(--text-secondary);
    pointer-events: none;
}

.form-control {
    width: 100%;
    padding: 0.75rem 1rem 0.75rem 2.5rem;
    /* Space for icon */
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    font-size: 1rem;
    transition: all 0.2s;
    background-color: #f8fafc;
}

.form-control:focus {
    outline: none;
    border-color: var(--primary-color);
    background-color: var(--surface-color);
    box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.1);
}

.form-control::placeholder {
    color: #94a3b8;
}

.auth-footer {
    text-align: center;
    margin-top: 2rem;
    padding-top: 1.5rem;
    border-top: 1px solid var(--border-color);
    font-size: 0.95rem;
    color: var(--text-secondary);
}

.auth-footer a {
    color: var(--primary-color);
    font-weight: 600;
}

.auth-footer a:hover {
    text-decoration: underline;
}