/* ============================================
   rivers-discharge.css — 世界主要河流年径流量排名
   页面专用样式
   ============================================ */

/* ---- Hero Section ---- */
.rivers-hero {
    min-height: 65vh;
    display: flex;
    align-items: center;
    justify-content: center;
    position: relative;
    overflow: hidden;
    background: linear-gradient(160deg, #0a1f2e 0%, #0d3b5c 40%, #0a1628 100%);
    padding-top: 72px;
}

.rivers-hero-canvas {
    position: absolute;
    top: 0; left: 0;
    width: 100%; height: 100%;
    z-index: 1;
}

.rivers-hero-content {
    position: relative;
    z-index: 2;
    text-align: center;
    color: white;
    max-width: 900px;
    padding: 0 var(--space-lg);
}

.rivers-hero-title {
    font-family: var(--font-heading);
    font-size: clamp(2rem, 5vw, 3.5rem);
    font-weight: 900;
    line-height: 1.15;
    margin-bottom: var(--space-lg);
    text-shadow: 0 2px 20px rgba(0,0,0,0.3);
}

.rivers-hero-title .highlight {
    background: linear-gradient(135deg, #4FC3F7, #29B6F6);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.rivers-hero-subtitle {
    font-size: clamp(1rem, 2vw, 1.15rem);
    color: rgba(255,255,255,0.75);
    margin-bottom: var(--space-2xl);
    line-height: 1.8;
    max-width: 700px;
    margin-left: auto;
    margin-right: auto;
}

.rivers-hero-stats {
    display: flex;
    justify-content: center;
    gap: var(--space-3xl);
    flex-wrap: wrap;
}

.rh-stat {
    text-align: center;
}

.rh-stat-num {
    display: block;
    font-family: var(--font-heading);
    font-size: clamp(1.75rem, 3.5vw, 2.5rem);
    font-weight: 900;
    background: linear-gradient(135deg, #fff, rgba(79,195,247,0.8));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    line-height: 1;
}

.rh-stat-label {
    font-size: 0.875rem;
    color: rgba(255,255,255,0.6);
    margin-top: var(--space-sm);
    letter-spacing: 0.05em;
}

/* ---- Stats Bar ---- */
.stats-bar-section {
    background: var(--color-card);
    border-bottom: 1px solid var(--color-border-light);
    padding: var(--space-xl) 0;
}

.stats-bar {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: var(--space-xl);
}

.stats-bar-item {
    display: flex;
    align-items: center;
    gap: var(--space-md);
    padding: var(--space-md);
    border-radius: var(--radius-lg);
    background: var(--color-bg);
    border: 1px solid var(--color-border-light);
}

.sbi-icon {
    font-size: 1.75rem;
    flex-shrink: 0;
}

.sbi-text {
    display: flex;
    flex-direction: column;
    gap: 2px;
}

.sbi-text strong {
    font-size: 0.9375rem;
    color: var(--color-text);
    font-weight: 600;
}

.sbi-text span {
    font-size: 0.8125rem;
    color: var(--color-text-secondary);
}

/* ---- Chart Container ---- */
.chart-container {
    background: linear-gradient(135deg, #0a1f2e, #0d2d47);
    border-radius: var(--radius-xl);
    padding: var(--space-xl);
    margin-bottom: var(--space-lg);
    box-shadow: var(--shadow-lg);
    overflow: hidden;
}

.chart-container canvas {
    width: 100%;
    height: auto;
    display: block;
}

.chart-legend-bar {
    display: flex;
    justify-content: center;
    gap: var(--space-xl);
    flex-wrap: wrap;
    margin-bottom: var(--space-lg);
    padding: var(--space-md);
    background: var(--color-card);
    border-radius: var(--radius-lg);
    border: 1px solid var(--color-border-light);
}

.clb-item {
    display: flex;
    align-items: center;
    gap: var(--space-sm);
    font-size: 0.875rem;
    color: var(--color-text-secondary);
    font-weight: 500;
}

.clb-dot {
    width: 12px; height: 12px;
    border-radius: 50%;
    display: inline-block;
}

.chart-note {
    background: var(--color-sky);
    border-radius: var(--radius-lg);
    padding: var(--space-lg);
    border-left: 4px solid var(--color-secondary);
}

.chart-note p {
    font-size: 0.875rem;
    color: var(--color-text-secondary);
    line-height: 1.8;
    margin-bottom: 0;
}

/* ---- Map Section ---- */
.map-container {
    background: linear-gradient(135deg, #0a1f2e, #0d2d47);
    border-radius: var(--radius-xl);
    padding: var(--space-xl);
    box-shadow: var(--shadow-lg);
    position: relative;
    display: flex;
    gap: var(--space-xl);
    align-items: flex-start;
}

.map-container canvas {
    flex: 1;
    width: 100%;
    height: auto;
    display: block;
    min-height: 400px;
}

.map-river-list {
    width: 200px;
    flex-shrink: 0;
    display: flex;
    flex-direction: column;
    gap: var(--space-sm);
}

.map-river-item {
    display: flex;
    align-items: center;
    gap: var(--space-sm);
    padding: var(--space-sm) var(--space-md);
    border-radius: var(--radius-md);
    background: rgba(255,255,255,0.05);
    border: 1px solid rgba(255,255,255,0.1);
    color: rgba(255,255,255,0.8);
    font-size: 0.8125rem;
    cursor: pointer;
    transition: var(--transition-fast);
}

.map-river-item:hover,
.map-river-item.active {
    background: rgba(255,255,255,0.15);
    border-color: rgba(255,255,255,0.3);
    color: white;
}

.map-river-item .mri-rank {
    width: 22px; height: 22px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 0.6875rem;
    font-weight: 700;
    flex-shrink: 0;
    background: rgba(255,255,255,0.15);
}

.map-river-item:hover .mri-rank,
.map-river-item.active .mri-rank {
    background: var(--color-primary-light);
}

.map-note {
    margin-top: var(--space-lg);
    text-align: center;
}

.map-note p {
    font-size: 0.8125rem;
    color: var(--color-text-muted);
    margin-bottom: 0;
}

/* ---- River Cards ---- */
.river-cards-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: var(--space-xl);
}

.river-card {
    background: var(--color-card);
    border-radius: var(--radius-xl);
    overflow: hidden;
    border: 1px solid var(--color-border-light);
    transition: var(--transition-base);
    display: flex;
    flex-direction: column;
}

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

.river-card-header {
    padding: var(--space-xl);
    display: flex;
    align-items: center;
    gap: var(--space-md);
    color: white;
    position: relative;
    overflow: hidden;
}

.river-card-header::before {
    content: '';
    position: absolute;
    top: 0; right: 0;
    width: 120px; height: 120px;
    background: rgba(255,255,255,0.05);
    border-radius: 50%;
    transform: translate(30%, -30%);
}

.river-rank {
    width: 48px; height: 48px;
    border-radius: 50%;
    background: rgba(255,255,255,0.2);
    backdrop-filter: blur(4px);
    display: flex;
    align-items: center;
    justify-content: center;
    font-family: var(--font-heading);
    font-size: 1.5rem;
    font-weight: 900;
    flex-shrink: 0;
    border: 2px solid rgba(255,255,255,0.3);
}

.river-header-info {
    flex: 1;
}

.river-header-info h3 {
    font-family: var(--font-heading);
    font-size: 1.25rem;
    margin-bottom: 2px;
    color: white;
}

.river-en {
    font-size: 0.8125rem;
    color: rgba(255,255,255,0.7);
    font-style: italic;
}

.river-discharge-badge {
    text-align: right;
    font-family: var(--font-heading);
    font-size: 1.5rem;
    font-weight: 900;
    color: white;
    line-height: 1;
}

.river-discharge-badge small {
    font-size: 0.75rem;
    font-weight: 400;
    color: rgba(255,255,255,0.7);
    display: block;
    margin-top: 2px;
}

.river-card-body {
    padding: var(--space-xl);
    flex: 1;
    display: flex;
    flex-direction: column;
    gap: var(--space-md);
}

.river-metrics {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: var(--space-sm);
    padding: var(--space-md);
    background: var(--color-bg);
    border-radius: var(--radius-lg);
}

.rm-item {
    display: flex;
    flex-direction: column;
    gap: 2px;
}

.rm-label {
    font-size: 0.75rem;
    color: var(--color-text-muted);
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

.rm-value {
    font-size: 0.9375rem;
    font-weight: 600;
    color: var(--color-text);
    font-family: var(--font-mono);
}

.river-countries {
    font-size: 0.875rem;
    color: var(--color-text-secondary);
    line-height: 1.7;
}

.river-countries strong {
    color: var(--color-text);
}

.river-desc {
    font-size: 0.9375rem;
    color: var(--color-text-secondary);
    line-height: 1.8;
}

.river-desc p {
    margin-bottom: var(--space-sm);
}

.river-desc p:last-child {
    margin-bottom: 0;
}

.river-desc strong {
    color: var(--color-text);
}

.river-fact {
    display: flex;
    gap: var(--space-sm);
    padding: var(--space-md);
    background: linear-gradient(135deg, #E3F2FD, #E8F5E9);
    border-radius: var(--radius-lg);
    border-left: 3px solid var(--color-secondary);
    margin-top: auto;
}

.fact-icon {
    font-size: 1.25rem;
    flex-shrink: 0;
}

.river-fact span:last-child {
    font-size: 0.875rem;
    color: var(--color-text-secondary);
    line-height: 1.7;
}

/* ---- Insights ---- */
.insights-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: var(--space-xl);
}

.insight-card {
    background: var(--color-card);
    border-radius: var(--radius-xl);
    padding: var(--space-2xl);
    border: 1px solid var(--color-border-light);
    transition: var(--transition-base);
}

.insight-card:hover {
    box-shadow: var(--shadow-md);
    border-color: var(--color-primary-light);
    transform: translateY(-4px);
}

.insight-icon {
    width: 56px; height: 56px;
    border-radius: var(--radius-lg);
    background: linear-gradient(135deg, var(--color-sky), var(--color-sky-dark));
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.75rem;
    margin-bottom: var(--space-lg);
}

.insight-card h4 {
    font-family: var(--font-heading);
    font-size: 1.125rem;
    margin-bottom: var(--space-sm);
    color: var(--color-text);
}

.insight-card p {
    font-size: 0.9375rem;
    color: var(--color-text-secondary);
    line-height: 1.8;
    margin-bottom: 0;
}

.insight-card p strong {
    color: var(--color-text);
}

/* ---- Data Table ---- */
.table-responsive {
    overflow-x: auto;
    border-radius: var(--radius-xl);
    box-shadow: var(--shadow-md);
    border: 1px solid var(--color-border-light);
}

.data-table {
    width: 100%;
    border-collapse: collapse;
    background: var(--color-card);
    font-size: 0.9375rem;
}

.data-table thead {
    background: linear-gradient(135deg, var(--color-primary-dark), var(--color-secondary-dark));
    color: white;
}

.data-table thead th {
    padding: var(--space-md) var(--space-lg);
    text-align: left;
    font-weight: 600;
    font-size: 0.875rem;
    white-space: nowrap;
}

.data-table thead th:first-child {
    border-radius: var(--radius-xl) 0 0 0;
}

.data-table thead th:last-child {
    border-radius: 0 var(--radius-xl) 0 0;
}

.data-table tbody tr {
    border-bottom: 1px solid var(--color-border-light);
    transition: var(--transition-fast);
}

.data-table tbody tr:hover {
    background: var(--color-sky);
}

.data-table tbody tr:last-child {
    border-bottom: none;
}

.data-table tbody td {
    padding: var(--space-md) var(--space-lg);
    color: var(--color-text);
}

.data-table tbody td strong {
    color: var(--color-text);
    font-weight: 600;
}

.rank-badge {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 28px; height: 28px;
    border-radius: 50%;
    font-size: 0.8125rem;
    font-weight: 700;
    color: white;
}

.rank-badge.rank-1 { background: linear-gradient(135deg, #FFD700, #FFA000); }
.rank-badge.rank-2 { background: linear-gradient(135deg, #C0C0C0, #90A4AE); }
.rank-badge.rank-3 { background: linear-gradient(135deg, #CD7F32, #8D6E63); }
.rank-badge.rank-4,
.rank-badge.rank-5,
.rank-badge.rank-6,
.rank-badge.rank-7,
.rank-badge.rank-8,
.rank-badge.rank-9,
.rank-badge.rank-10 { background: var(--color-secondary); }

/* ---- Sources Section ---- */
.source-link {
    display: inline-flex;
    align-items: center;
    gap: 4px;
    color: var(--color-secondary);
    font-weight: 600;
    font-size: 0.875rem;
    margin-top: var(--space-sm);
    transition: gap var(--transition-fast);
}

.source-link:hover {
    gap: 8px;
    color: var(--color-secondary-dark);
}

.citation-box {
    background: var(--color-card);
    border: 1px solid var(--color-border-light);
    border-radius: var(--radius-lg);
    padding: var(--space-xl);
    margin-top: var(--space-xl);
}

.citation-box h4 {
    font-family: var(--font-heading);
    margin-bottom: var(--space-md);
    color: var(--color-text);
}

.citation-format p {
    font-size: 0.875rem;
    color: var(--color-text-secondary);
    line-height: 1.8;
    margin-bottom: var(--space-sm);
    padding: var(--space-md);
    background: var(--color-bg);
    border-radius: var(--radius-md);
    font-family: var(--font-mono);
}

.citation-format p:last-child {
    margin-bottom: 0;
}

/* ---- Responsive ---- */
@media (max-width: 1023px) {
    .stats-bar { grid-template-columns: repeat(2, 1fr); }
    .river-cards-grid { grid-template-columns: 1fr; }
    .insights-grid { grid-template-columns: repeat(2, 1fr); }
    .map-container { flex-direction: column; }
    .map-river-list {
        width: 100%;
        flex-direction: row;
        flex-wrap: wrap;
    }
    .map-river-item { flex: 1; min-width: 140px; }
}

@media (max-width: 767px) {
    .stats-bar { grid-template-columns: 1fr; }
    .insights-grid { grid-template-columns: 1fr; }
    .river-metrics { grid-template-columns: 1fr 1fr; }
    .chart-legend-bar { gap: var(--space-md); }
    .rivers-hero-stats { gap: var(--space-xl); }
    .rh-stat-num { font-size: 1.5rem; }
    .data-table { font-size: 0.8125rem; }
    .data-table thead th,
    .data-table tbody td { padding: var(--space-sm); }
}

@media (max-width: 479px) {
    .river-card-header {
        flex-wrap: wrap;
        gap: var(--space-sm);
    }
    .river-discharge-badge {
        width: 100%;
        text-align: left;
        margin-top: var(--space-sm);
    }
    .river-metrics { grid-template-columns: 1fr; }
}