/* ===== APP LAYOUT ===== */
#app {
    min-height: 100vh;
    position: relative;
}

.page {
    min-height: 100vh;
    padding: var(--space-6);
    animation: fadeIn var(--transition-base);
}

.container {
    max-width: 720px;
    margin: 0 auto;
    width: 100%;
}

@media (min-width: 768px) {
    .page {
        padding: var(--space-12) var(--space-6);
    }
}

/* ===== HERO ===== */
.hero {
    text-align: center;
    margin-bottom: var(--space-12);
}

.logo {
    width: 64px;
    height: 64px;
    color: var(--purple-primary);
    margin: 0 auto var(--space-4);
    filter: drop-shadow(0 4px 12px var(--purple-glow));
}

.title {
    font-size: var(--text-2xl);
    font-weight: 700;
    letter-spacing: 0.05em;
    margin-bottom: var(--space-2);
    background: linear-gradient(135deg, var(--purple-light), var(--purple-primary));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.subtitle {
    font-size: var(--text-sm);
    color: var(--text-secondary);
    font-weight: 400;
}

/* ===== NAVIGATION ===== */
.nav-back {
    display: inline-flex;
    align-items: center;
    gap: var(--space-2);
    background: none;
    border: none;
    color: var(--text-secondary);
    font-size: var(--text-sm);
    font-family: var(--font-primary);
    cursor: pointer;
    padding: var(--space-2) 0;
    margin-bottom: var(--space-6);
    transition: color var(--transition-fast);
}

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

.nav-back svg {
    width: 16px;
    height: 16px;
}

/* ===== PAGE HEADER ===== */
.page-header {
    margin-bottom: var(--space-8);
}

.page-title {
    font-size: var(--text-xl);
    font-weight: 700;
    color: var(--text-primary);
    margin-bottom: var(--space-1);
}

.page-subtitle {
    font-size: var(--text-sm);
    color: var(--text-tertiary);
}

/* ===== SECTION HEADER ===== */
.section-header {
    display: flex;
    align-items: baseline;
    justify-content: space-between;
    margin-bottom: var(--space-4);
}

.section-title {
    font-size: var(--text-lg);
    font-weight: 600;
    color: var(--text-primary);
}

.section-count {
    font-size: var(--text-sm);
    color: var(--text-tertiary);
    font-family: var(--font-mono);
}

/* ===== ALPHABET JUMP ===== */
.alphabet-bar {
    display: flex;
    flex-wrap: wrap;
    gap: var(--space-1);
    justify-content: center;
    padding: var(--space-4) 0;
    margin-bottom: var(--space-6);
    position: sticky;
    top: 0;
    background: var(--bg-primary);
    z-index: 10;
    border-bottom: 1px solid var(--border-color);
}

.alphabet-letter {
    width: 28px;
    height: 28px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: var(--text-xs);
    font-weight: 600;
    color: var(--text-tertiary);
    border-radius: 4px;
    cursor: pointer;
    transition: all var(--transition-fast);
    background: none;
    border: none;
    font-family: var(--font-mono);
}

.alphabet-letter:hover {
    color: var(--purple-primary);
    background: rgba(139, 92, 246, 0.1);
}

.alphabet-letter.active {
    color: var(--purple-primary);
    background: rgba(139, 92, 246, 0.15);
}

.alphabet-letter.disabled {
    opacity: 0.3;
    cursor: default;
}

/* ===== LETTER GROUP ===== */
.letter-group {
    margin-bottom: var(--space-6);
}

.letter-group-title {
    font-size: var(--text-lg);
    font-weight: 700;
    color: var(--purple-light);
    margin-bottom: var(--space-3);
    padding-bottom: var(--space-2);
    border-bottom: 1px solid var(--border-color);
    font-family: var(--font-mono);
}

/* ===== BRAND GRID ===== */
.brand-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
    gap: var(--space-3);
    margin-bottom: var(--space-4);
}

/* ===== MODEL LIST ===== */
.model-list {
    display: flex;
    flex-direction: column;
    gap: var(--space-2);
}

.model-item {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: var(--space-3) var(--space-4);
    background: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    cursor: pointer;
    transition: all var(--transition-fast);
}

.model-item:hover {
    border-color: var(--purple-primary);
    background: var(--bg-tertiary);
}

.model-name {
    font-family: var(--font-mono);
    font-size: var(--text-sm);
    color: var(--text-primary);
}

.model-arrow {
    color: var(--text-tertiary);
    transition: transform var(--transition-fast);
}

.model-item:hover .model-arrow {
    color: var(--purple-primary);
    transform: translateX(4px);
}

/* ===== LOADING ===== */
.loading {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: var(--space-3);
    padding: var(--space-12);
    color: var(--text-tertiary);
    font-size: var(--text-sm);
}

.spinner {
    width: 20px;
    height: 20px;
    border: 2px solid var(--border-color);
    border-top-color: var(--purple-primary);
    border-radius: 50%;
    animation: spin 0.6s linear infinite;
}

@keyframes spin {
    to { transform: rotate(360deg); }
}

/* ===== EMPTY STATE ===== */
.empty-state {
    text-align: center;
    padding: var(--space-12);
    color: var(--text-tertiary);
}

.empty-state p {
    margin-bottom: var(--space-4);
}

/* ===== PRIVACY NOTE ===== */
.privacy-note {
    display: flex;
    align-items: center;
    gap: var(--space-2);
    margin-top: var(--space-4);
    padding: var(--space-3) var(--space-4);
    background: rgba(16, 185, 129, 0.05);
    border: 1px solid rgba(16, 185, 129, 0.15);
    border-radius: var(--radius-md);
    font-size: var(--text-xs);
    color: var(--success);
}

.privacy-note svg {
    width: 14px;
    height: 14px;
    flex-shrink: 0;
}