/* ========================================
   WeightTracker — Dark Theme CSS
   ======================================== */

:root {
    /* Colors */
    --bg-primary: #0a0e17;
    --bg-secondary: #111827;
    --bg-card: #1a2233;
    --bg-card-hover: #212d42;
    --bg-input: #0f1624;
    --border: #2a3548;
    --border-focus: #3b82f6;

    --text-primary: #f1f5f9;
    --text-secondary: #94a3b8;
    --text-muted: #64748b;

    --accent: #3b82f6;
    --accent-hover: #2563eb;
    --accent-glow: rgba(59, 130, 246, 0.15);
    --success: #10b981;
    --success-bg: rgba(16, 185, 129, 0.1);
    --danger: #ef4444;
    --danger-bg: rgba(239, 68, 68, 0.1);
    --warning: #f59e0b;
    --warning-bg: rgba(245, 158, 11, 0.1);
    --info: #06b6d4;

    /* Gradients */
    --gradient-accent: linear-gradient(135deg, #3b82f6, #8b5cf6);
    --gradient-success: linear-gradient(135deg, #10b981, #06b6d4);
    --gradient-card: linear-gradient(135deg, rgba(59, 130, 246, 0.05), rgba(139, 92, 246, 0.05));

    /* Spacing */
    --radius: 12px;
    --radius-sm: 8px;
    --radius-lg: 16px;

    /* Shadows */
    --shadow: 0 4px 24px rgba(0, 0, 0, 0.3);
    --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.2);
    --shadow-glow: 0 0 20px rgba(59, 130, 246, 0.15);
}

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

html {
    font-size: 16px;
    scroll-behavior: smooth;
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
    background: var(--bg-primary);
    color: var(--text-primary);
    line-height: 1.6;
    min-height: 100vh;
    -webkit-font-smoothing: antialiased;
}

/* ========== NAVBAR ========== */
.navbar {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 0 1.5rem;
    height: 64px;
    background: var(--bg-secondary);
    border-bottom: 1px solid var(--border);
    position: sticky;
    top: 0;
    z-index: 100;
    backdrop-filter: blur(12px);
}

.nav-brand a {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    text-decoration: none;
    color: var(--text-primary);
    font-weight: 700;
    font-size: 1.15rem;
}

.nav-icon { font-size: 1.4rem; }

.nav-links {
    display: flex;
    gap: 0.25rem;
}

.nav-links a {
    display: flex;
    align-items: center;
    gap: 0.4rem;
    padding: 0.5rem 0.9rem;
    border-radius: var(--radius-sm);
    text-decoration: none;
    color: var(--text-secondary);
    font-size: 0.875rem;
    font-weight: 500;
    transition: all 0.2s ease;
}

.nav-links a:hover {
    color: var(--text-primary);
    background: var(--accent-glow);
}

.nav-links a.active {
    color: var(--accent);
    background: var(--accent-glow);
}

.nav-link-icon { font-size: 1.1rem; }

.nav-toggle {
    display: none;
    flex-direction: column;
    gap: 4px;
    background: none;
    border: none;
    cursor: pointer;
    padding: 0.5rem;
}

.nav-toggle span {
    display: block;
    width: 22px;
    height: 2px;
    background: var(--text-secondary);
    border-radius: 2px;
    transition: all 0.2s;
}

.nav-actions { display: flex; align-items: center; }

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

/* ========== FLASH MESSAGES ========== */
.flash-messages { margin-bottom: 1rem; }

.flash {
    padding: 0.75rem 1rem;
    border-radius: var(--radius-sm);
    font-size: 0.875rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 0.5rem;
    animation: slideIn 0.3s ease;
}

.flash-success { background: var(--success-bg); color: var(--success); border: 1px solid rgba(16, 185, 129, 0.2); }
.flash-error { background: var(--danger-bg); color: var(--danger); border: 1px solid rgba(239, 68, 68, 0.2); }
.flash-info { background: rgba(6, 182, 212, 0.1); color: var(--info); border: 1px solid rgba(6, 182, 212, 0.2); }

.flash-close {
    background: none;
    border: none;
    color: inherit;
    font-size: 1.2rem;
    cursor: pointer;
    opacity: 0.7;
}

.flash-close:hover { opacity: 1; }

/* ========== PAGE HEADERS ========== */
.page-header {
    margin-bottom: 1.5rem;
}

.page-header h1 {
    font-size: 1.75rem;
    font-weight: 800;
    letter-spacing: -0.02em;
    background: var(--gradient-accent);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.page-header p {
    color: var(--text-secondary);
    font-size: 0.9rem;
    margin-top: 0.25rem;
}

/* ========== CARDS ========== */
.card {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 1.25rem;
    transition: all 0.2s ease;
}

.card:hover {
    border-color: rgba(59, 130, 246, 0.2);
    box-shadow: var(--shadow-glow);
}

.card-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    margin-bottom: 1rem;
}

.card-header h2 {
    font-size: 1rem;
    font-weight: 600;
    color: var(--text-primary);
}

.card-header .badge {
    font-size: 0.7rem;
    padding: 0.2rem 0.6rem;
    border-radius: 100px;
    background: var(--accent-glow);
    color: var(--accent);
    font-weight: 600;
}

/* ========== STAT CARDS ========== */
.stats-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
    gap: 1rem;
    margin-bottom: 1.5rem;
}

.stat-card {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 1.25rem;
    position: relative;
    overflow: hidden;
}

.stat-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 3px;
    background: var(--gradient-accent);
    opacity: 0;
    transition: opacity 0.2s;
}

.stat-card:hover::before { opacity: 1; }

.stat-label {
    font-size: 0.75rem;
    font-weight: 500;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    color: var(--text-muted);
    margin-bottom: 0.5rem;
}

.stat-value {
    font-size: 1.75rem;
    font-weight: 800;
    letter-spacing: -0.02em;
    color: var(--text-primary);
}

.stat-change {
    font-size: 0.8rem;
    font-weight: 500;
    margin-top: 0.25rem;
}

.stat-change.positive { color: var(--success); }
.stat-change.negative { color: var(--danger); }

/* ========== FORMS ========== */
.form-group {
    margin-bottom: 1rem;
}

.form-label {
    display: block;
    font-size: 0.8rem;
    font-weight: 500;
    color: var(--text-secondary);
    margin-bottom: 0.375rem;
}

.form-input {
    width: 100%;
    padding: 0.65rem 0.9rem;
    background: var(--bg-input);
    border: 1px solid var(--border);
    border-radius: var(--radius-sm);
    color: var(--text-primary);
    font-family: inherit;
    font-size: 0.9rem;
    transition: all 0.2s ease;
    outline: none;
}

.form-input:focus {
    border-color: var(--border-focus);
    box-shadow: 0 0 0 3px var(--accent-glow);
}

.form-input::placeholder { color: var(--text-muted); }

select.form-input {
    appearance: none;
    background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='12' height='12' fill='%2394a3b8' viewBox='0 0 16 16'%3E%3Cpath d='M8 11L3 6h10l-5 5z'/%3E%3C/svg%3E");
    background-repeat: no-repeat;
    background-position: right 0.75rem center;
    padding-right: 2rem;
}

.form-row {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(140px, 1fr));
    gap: 0.75rem;
}

.form-inline {
    display: flex;
    gap: 0.75rem;
    align-items: flex-end;
}

.form-inline .form-group { flex: 1; margin-bottom: 0; }

/* ========== BUTTONS ========== */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 0.4rem;
    padding: 0.65rem 1.25rem;
    font-family: inherit;
    font-size: 0.875rem;
    font-weight: 600;
    border: none;
    border-radius: var(--radius-sm);
    cursor: pointer;
    transition: all 0.2s ease;
    text-decoration: none;
    white-space: nowrap;
}

.btn-primary {
    background: var(--gradient-accent);
    color: white;
    box-shadow: 0 2px 12px rgba(59, 130, 246, 0.3);
}

.btn-primary:hover {
    transform: translateY(-1px);
    box-shadow: 0 4px 20px rgba(59, 130, 246, 0.4);
}

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

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

.btn-ghost {
    background: transparent;
    color: var(--text-secondary);
    border: 1px solid var(--border);
}

.btn-ghost:hover {
    color: var(--text-primary);
    border-color: var(--text-muted);
    background: var(--bg-card);
}

.btn-sm { padding: 0.4rem 0.8rem; font-size: 0.8rem; }
.btn-lg { padding: 0.85rem 1.75rem; font-size: 1rem; }
.btn-block { width: 100%; }

/* ========== TABLES ========== */
.table-wrap {
    overflow-x: auto;
    border-radius: var(--radius);
    border: 1px solid var(--border);
}

table {
    width: 100%;
    border-collapse: collapse;
}

th {
    text-align: left;
    padding: 0.75rem 1rem;
    font-size: 0.75rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    color: var(--text-muted);
    background: var(--bg-secondary);
    border-bottom: 1px solid var(--border);
}

td {
    padding: 0.75rem 1rem;
    font-size: 0.875rem;
    border-bottom: 1px solid var(--border);
    color: var(--text-secondary);
}

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

tr:hover td { background: var(--bg-card-hover); }

/* ========== LEADERBOARD ========== */
.rank-badge {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 28px;
    height: 28px;
    border-radius: 50%;
    font-weight: 700;
    font-size: 0.8rem;
}

.rank-1 { background: linear-gradient(135deg, #fbbf24, #f59e0b); color: #1a1a1a; }
.rank-2 { background: linear-gradient(135deg, #cbd5e1, #94a3b8); color: #1a1a1a; }
.rank-3 { background: linear-gradient(135deg, #d97706, #b45309); color: white; }
.rank-other { background: var(--bg-secondary); color: var(--text-muted); }

.progress-bar-track {
    width: 100%;
    height: 6px;
    background: var(--bg-secondary);
    border-radius: 3px;
    overflow: hidden;
}

.progress-bar-fill {
    height: 100%;
    border-radius: 3px;
    background: var(--gradient-accent);
    transition: width 0.5s ease;
}

/* ========== ACTIVITY FEED ========== */
.activity-item {
    display: flex;
    align-items: flex-start;
    gap: 0.75rem;
    padding: 0.75rem 0;
    border-bottom: 1px solid var(--border);
}

.activity-item:last-child { border-bottom: none; }

.activity-avatar {
    width: 32px;
    height: 32px;
    border-radius: 50%;
    background: var(--gradient-accent);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 0.75rem;
    font-weight: 700;
    color: white;
    flex-shrink: 0;
}

.activity-content { flex: 1; }

.activity-name {
    font-weight: 600;
    color: var(--text-primary);
    font-size: 0.875rem;
}

.activity-detail {
    font-size: 0.8rem;
    color: var(--text-muted);
    margin-top: 0.1rem;
}

/* ========== MILESTONES ========== */
.milestones-grid {
    display: flex;
    flex-wrap: wrap;
    gap: 0.5rem;
}

.milestone-badge {
    display: inline-flex;
    align-items: center;
    gap: 0.3rem;
    padding: 0.35rem 0.7rem;
    background: var(--accent-glow);
    border: 1px solid rgba(59, 130, 246, 0.2);
    border-radius: 100px;
    font-size: 0.75rem;
    font-weight: 500;
    color: var(--accent);
}

.milestone-badge.gold {
    background: rgba(245, 158, 11, 0.1);
    border-color: rgba(245, 158, 11, 0.2);
    color: var(--warning);
}

/* ========== CHARTS ========== */
.charts-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(350px, 1fr));
    gap: 1rem;
    margin-bottom: 1.5rem;
}

.chart-container {
    position: relative;
    height: 280px;
}

/* ========== AUTH PAGES ========== */
.auth-page {
    display: flex;
    align-items: center;
    justify-content: center;
    min-height: calc(100vh - 100px);
}

.auth-card {
    width: 100%;
    max-width: 420px;
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
    padding: 2rem;
    box-shadow: var(--shadow);
}

.auth-card h1 {
    font-size: 1.75rem;
    font-weight: 800;
    text-align: center;
    margin-bottom: 0.25rem;
    background: var(--gradient-accent);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.auth-card .auth-subtitle {
    text-align: center;
    color: var(--text-muted);
    font-size: 0.875rem;
    margin-bottom: 1.5rem;
}

.auth-card .auth-footer {
    text-align: center;
    margin-top: 1.25rem;
    font-size: 0.85rem;
    color: var(--text-muted);
}

.auth-card .auth-footer a {
    color: var(--accent);
    text-decoration: none;
    font-weight: 500;
}

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

/* ========== GRID LAYOUTS ========== */
.grid-2 {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 1rem;
}

.grid-3 {
    display: grid;
    grid-template-columns: 2fr 1fr;
    gap: 1rem;
}

/* ========== ANIMATIONS ========== */
@keyframes slideIn {
    from { transform: translateY(-8px); opacity: 0; }
    to { transform: translateY(0); opacity: 1; }
}

@keyframes fadeIn {
    from { opacity: 0; }
    to { opacity: 1; }
}

.htmx-added { animation: slideIn 0.3s ease; }
.htmx-settling { animation: fadeIn 0.2s ease; }

/* ========== DELETE BUTTON ========== */
.btn-icon {
    width: 30px;
    height: 30px;
    padding: 0;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    border-radius: 6px;
    background: transparent;
    border: 1px solid transparent;
    color: var(--text-muted);
    cursor: pointer;
    transition: all 0.2s;
    font-size: 0.9rem;
}

.btn-icon:hover {
    color: var(--danger);
    background: var(--danger-bg);
    border-color: rgba(239, 68, 68, 0.2);
}

/* ========== EMPTY STATE ========== */
.empty-state {
    text-align: center;
    padding: 3rem 1rem;
    color: var(--text-muted);
}

.empty-state-icon {
    font-size: 3rem;
    margin-bottom: 0.75rem;
    opacity: 0.5;
}

.empty-state h3 {
    font-size: 1.1rem;
    color: var(--text-secondary);
    margin-bottom: 0.5rem;
}

.empty-state p {
    font-size: 0.85rem;
    max-width: 300px;
    margin: 0 auto 1rem;
}

/* ========== RESPONSIVE ========== */
@media (max-width: 768px) {
    .navbar {
        padding: 0 1rem;
    }

    .nav-links {
        display: none;
        position: absolute;
        top: 64px;
        left: 0;
        right: 0;
        background: var(--bg-secondary);
        border-bottom: 1px solid var(--border);
        flex-direction: column;
        padding: 0.5rem;
    }

    .nav-links.open { display: flex; }

    .nav-toggle { display: flex; }

    .nav-actions { display: none; }

    .container { padding: 1rem; }

    .stats-grid {
        grid-template-columns: repeat(2, 1fr);
    }

    .charts-grid {
        grid-template-columns: 1fr;
    }

    .grid-2, .grid-3 {
        grid-template-columns: 1fr;
    }

    .form-inline {
        flex-direction: column;
        align-items: stretch;
    }

    .form-inline .form-group { margin-bottom: 0.75rem; }

    .page-header h1 { font-size: 1.4rem; }

    .stat-value { font-size: 1.4rem; }

    .auth-card { margin: 1rem; padding: 1.5rem; }

    .table-wrap {
        font-size: 0.8rem;
    }

    th, td { padding: 0.5rem 0.65rem; }
}

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