:root {
    /* Color Palette - Vibrant & Student-Focused (Energetic Teal & Deep Navy) */
    --bg-primary: #0F172A;
    --bg-secondary: #1E293B;
    --accent-primary: #2DD4BF; /* Teal */
    --accent-secondary: #F472B6; /* Pink accent */
    --text-primary: #F8FAFC;
    --text-secondary: #94A3B8;
    --border-color: #334155;
    --card-bg: #1E293B;
    --success: #4ADE80;
    --warning: #FBBF24;
    
    /* Spacing & Sizing */
    --spacing-xs: 4px;
    --spacing-sm: 8px;
    --spacing-md: 16px;
    --spacing-lg: 24px;
    --spacing-xl: 32px;
    --radius-sm: 8px;
    --radius-md: 16px;
    --radius-lg: 24px;
    
    /* Typography */
    --font-main: 'Outfit', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
}

* {
    box-sizing: border-box;
    -webkit-tap-highlight-color: transparent;
}

body {
    margin: 0;
    padding: 0;
    font-family: var(--font-main);
    background-color: var(--bg-primary);
    color: var(--text-primary);
    line-height: 1.5;
    overflow-x: hidden;
    min-height: 100vh;
}

/* Layout Containers */
.app-container {
    max-width: 480px; /* Mobile focused max-width */
    margin: 0 auto;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    position: relative;
    padding-bottom: 80px; /* Space for bottom nav */
}

/* Typography */
h1, h2, h3, p { margin: 0; }
h1 { font-size: 28px; font-weight: 700; }
h2 { font-size: 20px; font-weight: 600; }
.text-small { font-size: 14px; color: var(--text-secondary); }

/* Components */

/* Header */
.header {
    padding: var(--spacing-lg) var(--spacing-md);
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.user-profile {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
}

.avatar-placeholder {
    width: 40px;
    height: 40px;
    border-radius: 50%;
    background: linear-gradient(135deg, var(--accent-primary), var(--accent-secondary));
    border: 2px solid var(--border-color);
}

/* Stats Cards */
.stats-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--spacing-md);
    padding: 0 var(--spacing-md) var(--spacing-lg);
}

.stat-card {
    background: var(--card-bg);
    padding: var(--spacing-md);
    border-radius: var(--radius-md);
    border: 1px solid var(--border-color);
}

.stat-value {
    font-size: 24px;
    font-weight: 700;
    color: var(--accent-primary);
    display: block;
}

/* Section Controls */
.section-header {
    padding: 0 var(--spacing-md) var(--spacing-md);
    display: flex;
    justify-content: space-between;
    align-items: flex-end;
}

/* Workout/Diet Cards */
.scroll-container {
    display: flex;
    overflow-x: auto;
    gap: var(--spacing-md);
    padding: 0 var(--spacing-md) var(--spacing-lg);
    scrollbar-width: none;
}
.scroll-container::-webkit-scrollbar { display: none; }

.plan-card {
    min-width: 260px;
    background: var(--card-bg);
    border-radius: var(--radius-lg);
    overflow: hidden;
    border: 1px solid var(--border-color);
    position: relative;
}

.plan-image-placeholder {
    height: 160px;
    background: #2D3748;
    position: relative;
    display: flex;
    align-items: center;
    justify-content: center;
}

.plan-badge {
    position: absolute;
    top: 12px;
    left: 12px;
    background: rgba(0,0,0,0.6);
    backdrop-filter: blur(4px);
    padding: 4px 10px;
    border-radius: 100px;
    font-size: 12px;
    font-weight: 600;
}

.plan-badge.beginner { background: rgba(45, 212, 191, 0.2); color: var(--accent-primary); }
.plan-badge.intermediate { background: rgba(244, 114, 182, 0.2); color: var(--accent-secondary); }

.tracker-header {
    display: flex; 
    justify-content: space-between; 
    align-items: center;
}

.icon-large { width: 48px; height: 48px; opacity: 0.3; }
.icon-medium { width: 32px; height: 32px; opacity: 0.3; }
.icon-white { stroke: white; }

.see-all-link {
    text-decoration: none; 
    color: var(--accent-primary);
}

.diet-card-img { height: 120px; }
.diet-card-title { font-size: 16px; }

.bar-40 { height: 40%; }
.bar-60 { height: 60%; }
.bar-85 { height: 85%; }
.bar-30 { height: 30%; }
.bar-50 { height: 50%; }
.bar-20 { height: 20%; }
.bar-10 { height: 10%; }

.m-b-16 { margin-bottom: 16px; }
.p-x-16 { padding-left: 16px; padding-right: 16px; }
.flex-center { display: flex; flex-direction: column; align-items: center; text-align: center; }
.flex-row-center { display: flex; align-items: center; gap: 16px; }
.icon-m-8 { width: 32px; height: 32px; margin-bottom: 8px; }
.w-100 { min-width: 100%; width: 100%; }
.progress-bar-container { height: 8px; background: var(--bg-secondary); border-radius: 4px; overflow: hidden; }
.progress-bar { height: 100%; }
.btn-small { padding: 6px 12px; font-size: 12px; }
.border-accent { border-left: 4px solid var(--accent-primary); }
.border-secondary { border-left: 4px solid var(--accent-secondary); }

.plan-content {
    padding: var(--spacing-md);
}

.plan-title {
    font-size: 18px;
    font-weight: 600;
    margin-bottom: 4px;
}

/* Progress Tracker Section */
.tracker-section {
    padding: 0 var(--spacing-md) var(--spacing-lg);
}

.tracker-card {
    background: linear-gradient(135deg, #1E293B 0%, #0F172A 100%);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-lg);
    padding: var(--spacing-lg);
}

.day-strip {
    display: flex;
    justify-content: space-between;
    margin-top: var(--spacing-md);
}

.day-circle {
    width: 40px;
    height: 40px;
    border-radius: 50%;
    border: 2px solid var(--border-color);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 12px;
    font-weight: 600;
    transition: all 0.3s ease;
}

.day-circle.active {
    background: var(--accent-primary);
    border-color: var(--accent-primary);
    color: var(--bg-primary);
}

.day-circle.completed {
    background: var(--success);
    border-color: var(--success);
    color: var(--bg-primary);
}

/* Bottom Navigation */
.bottom-nav {
    position: fixed;
    bottom: 0;
    left: 50%;
    transform: translateX(-50%);
    width: 100%;
    max-width: 480px;
    background: rgba(15, 23, 42, 0.8);
    backdrop-filter: blur(12px);
    display: flex;
    justify-content: space-around;
    padding: 12px 0 24px;
    border-top: 1px solid var(--border-color);
    z-index: 100;
}

.nav-item {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 4px;
    color: var(--text-secondary);
    text-decoration: none;
    font-size: 12px;
}

.nav-item.active {
    color: var(--accent-primary);
}

.nav-icon {
    width: 24px;
    height: 24px;
}

/* Buttons */
.btn {
    padding: 12px 24px;
    border-radius: var(--radius-md);
    border: none;
    font-weight: 600;
    cursor: pointer;
    font-family: inherit;
    transition: transform 0.1s;
}

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

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

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

/* Icons (SVG) placeholders */
.icon {
    width: 20px;
    height: 20px;
    stroke-width: 2;
    stroke: currentColor;
    fill: none;
}

/* Chart Placeholder */
.chart-container {
    height: 120px;
    display: flex;
    align-items: flex-end;
    gap: 8px;
    margin-top: 20px;
}

.chart-bar {
    flex: 1;
    background: var(--border-color);
    border-radius: 4px 4px 0 0;
    transition: height 0.5s ease;
}

.chart-bar.highlight {
    background: var(--accent-secondary);
}

/* Auth Pages Style */
.auth-page {
    padding: var(--spacing-xl) var(--spacing-lg);
    display: flex;
    flex-direction: column;
    justify-content: center;
    min-height: 100vh;
}

.form-group {
    margin-bottom: var(--spacing-lg);
}

.label {
    display: block;
    margin-bottom: var(--spacing-sm);
    color: var(--text-secondary);
}

.input {
    width: 100%;
    background: var(--bg-secondary);
    border: 1px solid var(--border-color);
    padding: 14px;
    border-radius: var(--radius-md);
    color: var(--text-primary);
    font-size: 16px;
}

.input:focus {
    outline: none;
    border-color: var(--accent-primary);
}

/* Floating Action Button (FAB) */
.fab {
    position: fixed;
    bottom: 100px;
    right: 20px;
    width: 56px;
    height: 56px;
    border-radius: 28px;
    background: var(--accent-secondary);
    color: white;
    display: flex;
    align-items: center;
    justify-content: center;
    box-shadow: 0 4px 20px rgba(244, 114, 182, 0.4);
    z-index: 90;
    text-decoration: none;
}