:root {
    --primary: #1a73e8;
    --primary-dark: #1557b0;
    --secondary: #34a853;
    --danger: #ea4335;
    --warning: #fbbc04;
    --bg: #f8f9fa;
    --card-bg: #ffffff;
    --text: #202124;
    --text-muted: #5f6368;
    --border: #dadce0;
    --radius: 8px;
    --shadow: 0 1px 3px rgba(0,0,0,0.12), 0 1px 2px rgba(0,0,0,0.08);
}

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

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    background: var(--bg);
    color: var(--text);
    line-height: 1.6;
}

#app {
    max-width: 1100px;
    margin: 0 auto;
    padding: 20px;
}

header {
    text-align: center;
    margin-bottom: 24px;
}

header h1 {
    font-size: 2rem;
    color: var(--text);
}

.subtitle {
    color: var(--text-muted);
    font-size: 1rem;
}

/* Tabs */
.tabs {
    display: flex;
    gap: 4px;
    margin-bottom: 20px;
    border-bottom: 2px solid var(--border);
    padding-bottom: 0;
}

.tab {
    padding: 10px 20px;
    border: none;
    background: none;
    font-size: 0.95rem;
    font-weight: 500;
    color: var(--text-muted);
    cursor: pointer;
    border-bottom: 2px solid transparent;
    margin-bottom: -2px;
    transition: color 0.2s, border-color 0.2s;
}

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

.tab.active {
    color: var(--primary);
    border-bottom-color: var(--primary);
}

/* Tab content */
.tab-content {
    display: none;
}

.tab-content.active {
    display: block;
}

/* Cards */
.card {
    background: var(--card-bg);
    border-radius: var(--radius);
    box-shadow: var(--shadow);
    padding: 24px;
    margin-bottom: 20px;
}

.card h2 {
    font-size: 1.25rem;
    margin-bottom: 16px;
    color: var(--text);
}

.card h3 {
    font-size: 1rem;
    margin: 16px 0 12px;
    color: var(--text-muted);
}

/* Forms */
.form-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
    gap: 16px;
    margin-bottom: 16px;
}

.form-group {
    display: flex;
    flex-direction: column;
}

.form-group label {
    font-size: 0.8rem;
    font-weight: 500;
    color: var(--text-muted);
    margin-bottom: 4px;
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.form-group input,
.form-group select {
    padding: 8px 12px;
    border: 1px solid var(--border);
    border-radius: 4px;
    font-size: 0.95rem;
    transition: border-color 0.2s;
}

.form-group input:focus,
.form-group select:focus {
    outline: none;
    border-color: var(--primary);
    box-shadow: 0 0 0 2px rgba(26, 115, 232, 0.1);
}

/* Buttons */
.btn {
    padding: 8px 20px;
    border: none;
    border-radius: 4px;
    font-size: 0.9rem;
    font-weight: 500;
    cursor: pointer;
    transition: background 0.2s, transform 0.1s;
}

.btn:active {
    transform: scale(0.98);
}

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

.btn-primary:hover {
    background: var(--primary-dark);
}

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

.btn-secondary:hover {
    background: #2d9249;
}

.btn-danger {
    background: var(--danger);
    color: white;
    padding: 4px 10px;
    font-size: 0.8rem;
}

.btn-large {
    padding: 12px 32px;
    font-size: 1.1rem;
}

/* Fish list */
#fish-list {
    margin-bottom: 16px;
}

.fish-item {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 10px 14px;
    border: 1px solid var(--border);
    border-radius: 4px;
    margin-bottom: 8px;
    background: var(--bg);
}

.fish-item .fish-info {
    font-size: 0.9rem;
}

.fish-item .fish-info strong {
    margin-right: 12px;
}

.fish-item .fish-info span {
    color: var(--text-muted);
    margin-right: 8px;
    font-size: 0.85rem;
}

/* Sim controls */
.sim-controls {
    display: flex;
    align-items: center;
    gap: 16px;
}

.status {
    font-size: 0.9rem;
    color: var(--text-muted);
}

/* Table */
table {
    width: 100%;
    border-collapse: collapse;
    font-size: 0.9rem;
}

th, td {
    padding: 10px 12px;
    text-align: right;
    border-bottom: 1px solid var(--border);
}

th {
    text-align: right;
    font-weight: 600;
    color: var(--text-muted);
    font-size: 0.8rem;
    text-transform: uppercase;
}

th:first-child, td:first-child {
    text-align: left;
}

/* Charts */
canvas {
    max-height: 300px;
}

/* Hint text */
.hint {
    color: var(--text-muted);
    font-size: 0.85rem;
    margin-bottom: 12px;
}

/* Responsive */
@media (max-width: 768px) {
    .form-grid {
        grid-template-columns: 1fr 1fr;
    }
    .tabs {
        flex-wrap: wrap;
    }
    #app {
        padding: 12px;
    }
}

@media (max-width: 480px) {
    .form-grid {
        grid-template-columns: 1fr;
    }
}