/* Beginner-friendly modern UI (no frameworks) */

:root {
    --bg: #0b1220;
    --surface: rgba(255, 255, 255, 0.08);
    --surface-2: rgba(255, 255, 255, 0.12);
    --card: rgba(255, 255, 255, 0.10);
    --border: rgba(255, 255, 255, 0.14);
    --text: rgba(255, 255, 255, 0.92);
    --muted: rgba(255, 255, 255, 0.70);
    --brand: #22c55e;
    --brand-2: #16a34a;
    --danger: #ef4444;
    --warning: #f59e0b;
    --shadow: 0 12px 40px rgba(0, 0, 0, 0.35);
    --radius: 14px;
}

* { box-sizing: border-box; }

html, body {
    height: 100%;
}

body {
    margin: 0;
    font-family: ui-sans-serif, system-ui, -apple-system, Segoe UI, Roboto, Arial, sans-serif;
    color: var(--text);
    background:
        radial-gradient(1000px 600px at 20% 10%, rgba(34, 197, 94, 0.25), transparent 60%),
        radial-gradient(900px 500px at 90% 25%, rgba(59, 130, 246, 0.20), transparent 55%),
        linear-gradient(180deg, #070b14 0%, #0b1220 55%, #070b14 100%);
}

.container {
    max-width: 800px;
    margin: 0 auto;
    padding: 28px 18px 40px;
}

.navbar {
    display: flex;
    justify-content: space-between;
    align-items: center;
    background: linear-gradient(135deg, rgba(34, 197, 94, 0.24), rgba(59, 130, 246, 0.12));
    padding: 16px 18px;
    border-radius: var(--radius);
    margin-bottom: 18px;
    border: 1px solid var(--border);
    box-shadow: var(--shadow);
}

.navbar h1 {
    font-size: 18px;
    letter-spacing: 0.2px;
    margin: 0;
}

.dashboard-link {
    color: var(--text);
    text-decoration: none;
    font-weight: 600;
    padding: 10px 14px;
    background: rgba(255, 255, 255, 0.12);
    border: 1px solid rgba(255, 255, 255, 0.18);
    border-radius: 999px;
    transition: transform 0.15s ease, background-color 0.15s ease, border-color 0.15s ease;
}

.dashboard-link:hover {
    background: rgba(255, 255, 255, 0.16);
    border-color: rgba(255, 255, 255, 0.26);
    transform: translateY(-1px);
}

.payment-container {
    background: var(--card);
    border-radius: var(--radius);
    box-shadow: var(--shadow);
    padding: 24px;
    border: 1px solid var(--border);
    backdrop-filter: blur(10px);
}

.payment-form h2 {
    text-align: center;
    margin-bottom: 10px;
    color: var(--text);
    font-size: 26px;
    margin-top: 0;
}

.subtitle {
    text-align: center;
    margin-bottom: 22px;
    color: var(--muted);
    font-size: 14px;
    line-height: 1.35;
}

.form-group {
    margin-bottom: 20px;
}

label {
    display: block;
    margin-bottom: 8px;
    color: var(--muted);
    font-weight: 600;
    font-size: 13px;
}

input {
    width: 100%;
    padding: 12px;
    border: 1px solid rgba(255, 255, 255, 0.16);
    background: rgba(0, 0, 0, 0.22);
    color: var(--text);
    border-radius: 12px;
    font-size: 16px;
    transition: border-color 0.15s ease, box-shadow 0.15s ease, background-color 0.15s ease;
}

input:focus {
    outline: none;
    border-color: rgba(34, 197, 94, 0.55);
    box-shadow: 0 0 0 4px rgba(34, 197, 94, 0.18);
}

input:invalid {
    border-color: rgba(239, 68, 68, 0.55);
}

select {
    width: 100%;
    padding: 12px;
    border: 1px solid rgba(255, 255, 255, 0.16);
    background: rgba(0, 0, 0, 0.22);
    color: var(--text);
    border-radius: 12px;
    font-size: 16px;
    transition: border-color 0.15s ease, box-shadow 0.15s ease, background-color 0.15s ease;
}

select:focus {
    outline: none;
    border-color: rgba(34, 197, 94, 0.55);
    box-shadow: 0 0 0 4px rgba(34, 197, 94, 0.18);
}

.error {
    color: rgba(252, 165, 165, 0.95);
    font-size: 12px;
    margin-top: 5px;
    display: block;
    font-weight: 600;
}

.pay-button {
    width: 100%;
    padding: 15px;
    background: linear-gradient(135deg, var(--brand), rgba(59, 130, 246, 0.65));
    color: white;
    border: none;
    border-radius: 12px;
    font-size: 18px;
    font-weight: 700;
    cursor: pointer;
    transition: transform 0.15s ease, filter 0.15s ease, opacity 0.15s ease;
}

.pay-button:hover {
    transform: translateY(-1px);
    filter: brightness(1.03);
}

.pay-button:disabled {
    opacity: 0.6;
    cursor: not-allowed;
    transform: none;
}

.loading {
    text-align: center;
    color: var(--muted);
    margin-top: 20px;
    padding: 15px;
    background: rgba(255, 255, 255, 0.08);
    border: 1px solid var(--border);
    border-radius: 12px;
    font-weight: 600;
}

.success {
    text-align: center;
    color: rgba(134, 239, 172, 0.95);
    margin-top: 20px;
    padding: 15px;
    background: rgba(34, 197, 94, 0.12);
    border: 1px solid rgba(34, 197, 94, 0.28);
    border-radius: 12px;
    font-weight: 700;
}

.error-message {
    text-align: center;
    color: rgba(252, 165, 165, 0.95);
    margin-top: 20px;
    padding: 15px;
    background: rgba(239, 68, 68, 0.12);
    border: 1px solid rgba(239, 68, 68, 0.28);
    border-radius: 12px;
    font-weight: 700;
}

.hidden {
    display: none !important;
}

/* Dashboard specific styles */
.dashboard-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 28px 18px 40px;
    min-height: 100vh;
    color: var(--text);
}

.dashboard-container h1 {
    color: var(--text);
    text-align: center;
    margin-bottom: 30px;
    font-size: 34px;
    letter-spacing: 0.2px;
    margin-top: 6px;
}

.stats-card {
    background: var(--card);
    padding: 22px;
    border-radius: var(--radius);
    box-shadow: var(--shadow);
    margin-bottom: 30px;
    border: 1px solid var(--border);
    backdrop-filter: blur(10px);
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.stats-card:hover {
    transform: translateY(-3px);
}

.stats-card h3 {
    color: var(--text);
    margin-bottom: 20px;
    font-size: 18px;
    font-weight: 600;
    text-align: center;
    border-bottom: 1px solid rgba(255, 255, 255, 0.14);
    padding-bottom: 10px;
}

.stats-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 15px;
    margin-top: 20px;
}

.stat-item {
    background: rgba(255, 255, 255, 0.10);
    color: var(--text);
    padding: 16px 14px;
    border-radius: 14px;
    text-align: center;
    border: 1px solid rgba(255, 255, 255, 0.14);
    transition: transform 0.15s ease, background-color 0.15s ease;
}

.stat-item:hover {
    transform: translateY(-1px);
    background: rgba(255, 255, 255, 0.12);
}

.stat-value {
    font-size: 28px;
    font-weight: bold;
    margin-bottom: 5px;
}

.stat-label {
    font-size: 14px;
    opacity: 0.9;
}

.payments-container {
    background: var(--card);
    padding: 22px;
    border-radius: var(--radius);
    box-shadow: var(--shadow);
    border: 1px solid var(--border);
    backdrop-filter: blur(10px);
}

.filter-bar {
    display: flex;
    gap: 12px;
    flex-wrap: wrap;
    margin-bottom: 14px;
}

.filter-bar input {
    flex: 1 1 220px;
    min-width: 200px;
}

.filter-bar select {
    flex: 0 1 180px;
    min-width: 160px;
}

.conversion-row {
    display: flex;
    gap: 12px;
    flex-wrap: wrap;
}

.conversion-row > * {
    flex: 1 1 180px;
    min-width: 180px;
}

.charts-container {
    background: var(--card);
    padding: 22px;
    border-radius: var(--radius);
    box-shadow: var(--shadow);
    border: 1px solid var(--border);
    backdrop-filter: blur(10px);
    margin-bottom: 24px;
}

.charts-container h3 {
    color: var(--text);
    margin-bottom: 16px;
    font-size: 18px;
    font-weight: 600;
    text-align: center;
    border-bottom: 1px solid rgba(255, 255, 255, 0.14);
    padding-bottom: 10px;
}

.charts-grid {
    display: grid;
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 14px;
}

.chart-card {
    background: rgba(255, 255, 255, 0.08);
    border: 1px solid rgba(255, 255, 255, 0.14);
    border-radius: 14px;
    padding: 14px;
}

.chart-title {
    color: var(--text);
    font-weight: 700;
    font-size: 14px;
    margin-bottom: 10px;
    text-align: center;
}

.chart-caption {
    margin-top: 10px;
    color: var(--muted);
    font-size: 12px;
    line-height: 1.3;
    text-align: center;
}

.chart-card canvas {
    display: block;
    width: 100%;
    height: 260px;
    border-radius: 12px;
    background: rgba(0, 0, 0, 0.18);
    border: 1px solid rgba(255, 255, 255, 0.10);
}

.payments-container h3 {
    color: var(--text);
    margin-bottom: 20px;
    font-size: 18px;
    font-weight: 600;
    text-align: center;
    border-bottom: 1px solid rgba(255, 255, 255, 0.14);
    padding-bottom: 10px;
}

#paymentList {
    list-style: none;
    padding: 0;
    max-height: 400px;
    overflow-y: auto;
    margin: 0;
}

.payment-entry {
    background: rgba(255, 255, 255, 0.08);
    padding: 16px;
    border: 1px solid rgba(255, 255, 255, 0.14);
    border-radius: 14px;
    margin-bottom: 15px;
    transition: all 0.3s ease;
    border-left: 4px solid rgba(34, 197, 94, 0.75);
}

.payment-entry:hover {
    transform: translateX(5px);
    border-left-color: rgba(59, 130, 246, 0.75);
}

.payment-name {
    font-weight: bold;
    color: var(--text);
    font-size: 16px;
    margin-bottom: 5px;
}

.payment-amount {
    color: rgba(134, 239, 172, 0.95);
    font-weight: bold;
    font-size: 18px;
}

.entry-details {
    font-size: 13px;
    color: var(--muted);
    margin-top: 8px;
    display: flex;
    justify-content: space-between;
    flex-wrap: wrap;
}

.entry-actions {
    display: flex;
    gap: 10px;
    margin-top: 12px;
    flex-wrap: wrap;
}

.action-btn {
    border: 1px solid rgba(255, 255, 255, 0.16);
    background: rgba(255, 255, 255, 0.10);
    color: var(--text);
    padding: 10px 12px;
    border-radius: 12px;
    font-weight: 700;
    cursor: pointer;
    transition: transform 0.15s ease, background-color 0.15s ease, border-color 0.15s ease;
}

.action-btn:hover {
    transform: translateY(-1px);
    background: rgba(255, 255, 255, 0.12);
    border-color: rgba(255, 255, 255, 0.24);
}

.action-success {
    border-color: rgba(34, 197, 94, 0.35);
    background: rgba(34, 197, 94, 0.14);
}

.action-fail {
    border-color: rgba(239, 68, 68, 0.35);
    background: rgba(239, 68, 68, 0.14);
}

.status-badge {
    padding: 4px 8px;
    border-radius: 4px;
    font-size: 11px;
    font-weight: bold;
    text-transform: uppercase;
}

.status-success {
    background: rgba(34, 197, 94, 0.18);
    color: rgba(134, 239, 172, 0.95);
    border: 1px solid rgba(34, 197, 94, 0.25);
}

.status-pending {
    background: rgba(245, 158, 11, 0.18);
    color: rgba(253, 230, 138, 0.95);
    border: 1px solid rgba(245, 158, 11, 0.25);
}

.status-failed {
    background: rgba(239, 68, 68, 0.18);
    color: rgba(252, 165, 165, 0.95);
    border: 1px solid rgba(239, 68, 68, 0.25);
}

.back-link {
    display: inline-block;
    margin-bottom: 20px;
    color: var(--text);
    text-decoration: none;
    font-weight: 500;
    background: rgba(255, 255, 255, 0.12);
    padding: 10px 20px;
    border-radius: 25px;
    transition: all 0.3s ease;
    backdrop-filter: blur(10px);
    border: 1px solid rgba(255, 255, 255, 0.18);
}

.back-link:hover {
    background: rgba(255, 255, 255, 0.16);
    transform: translateY(-2px);
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.2);
}

.empty-state {
    text-align: center;
    padding: 40px 20px;
    color: var(--muted);
}

.empty-state-icon {
    font-size: 48px;
    margin-bottom: 15px;
    opacity: 0.5;
}

.empty-state-text {
    font-size: 16px;
    margin-bottom: 10px;
}

.empty-state-subtext {
    font-size: 14px;
    opacity: 0.7;
}

/* Mobile responsiveness */
@media (max-width: 600px) {
    .container {
        padding: 18px 14px 28px;
    }
    
    .navbar {
        flex-direction: column;
        text-align: center;
        gap: 10px;
    }
    
    .navbar h1 {
        font-size: 18px;
    }
    
    .payment-container {
        padding: 18px;
    }
    
    .payment-form h2 {
        font-size: 24px;
    }
    
    .dashboard-container {
        padding: 18px 14px 28px;
    }
    
    .dashboard-container h1 {
        font-size: 26px;
    }
    
    .stats-grid {
        grid-template-columns: 1fr;
    }

    .charts-grid {
        grid-template-columns: 1fr;
    }
    
    .filter-bar input,
    .filter-bar select {
        flex: 1 1 100%;
        min-width: 0;
    }

    .conversion-row > * {
        flex: 1 1 100%;
        min-width: 0;
    }

    .entry-details {
        flex-direction: column;
        gap: 5px;
    }
}