:root {
    --primary: #1a1a2e;
    --accent: #e94560;
    --bg: #f8f9fa;
    --card-bg: #ffffff;
    --text: #212529;
    --muted: #6c757d;
}

body {
    background: var(--bg);
    color: var(--text);
    font-family: 'Segoe UI', system-ui, sans-serif;
    padding-bottom: 80px; /* под bottom-nav */
}

/* Шапка */
.app-header {
    background: var(--primary);
    color: #fff;
    padding: 12px 16px;
    position: sticky;
    top: 0;
    z-index: 100;
}

/* Нижняя навигация (мобильная) */
.bottom-nav {
    position: fixed;
    bottom: 0;
    left: 0;
    right: 0;
    background: var(--primary);
    display: flex;
    justify-content: space-around;
    padding: 8px 0;
    z-index: 100;
}
.bottom-nav a {
    color: rgba(255,255,255,0.6);
    text-decoration: none;
    display: flex;
    flex-direction: column;
    align-items: center;
    font-size: 11px;
    gap: 2px;
}
.bottom-nav a.active,
.bottom-nav a:hover {
    color: var(--accent);
}
.bottom-nav .nav-icon {
    font-size: 20px;
}

/* Карточки */
.stat-card {
    background: var(--card-bg);
    border-radius: 12px;
    padding: 16px;
    box-shadow: 0 2px 8px rgba(0,0,0,0.06);
}

/* Прогресс-бар семестра */
.semester-bar .progress {
    height: 8px;
    border-radius: 4px;
}

/* Счётчик до сессии */
.session-countdown {
    background: linear-gradient(135deg, var(--accent), #c23152);
    color: #fff;
    border-radius: 12px;
    padding: 16px;
    text-align: center;
}
.session-countdown .days-count {
    font-size: 48px;
    font-weight: 700;
    line-height: 1;
}

/* PWA install banner */
#pwa-install-banner {
    position: fixed;
    bottom: 70px;
    left: 12px;
    right: 12px;
    background: var(--primary);
    color: #fff;
    border-radius: 12px;
    padding: 12px 16px;
    display: none;
    z-index: 200;
    box-shadow: 0 4px 16px rgba(0,0,0,0.2);
}