/* ===== CSS Variables & Themes ===== */
:root {
    /* Light Theme */
    --bg-primary: #f8fafc;
    --bg-secondary: #ffffff;
    --bg-tertiary: #f1f5f9;
    --bg-card: #ffffff;
    --bg-card-hover: #f8fafc;
    
    --text-primary: #0f172a;
    --text-secondary: #475569;
    --text-tertiary: #64748b;
    --text-muted: #94a3b8;
    
    --border-color: #e2e8f0;
    --border-light: #f1f5f9;
    
    --accent-primary: #3b82f6;
    --accent-secondary: #6366f1;
    --accent-gradient: linear-gradient(135deg, #3b82f6 0%, #6366f1 100%);
    
    --success: #10b981;
    --warning: #f59e0b;
    --danger: #ef4444;
    --info: #06b6d4;
    
    --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
    --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.1), 0 10px 10px -5px rgba(0, 0, 0, 0.04);
    
    --radius-sm: 6px;
    --radius-md: 10px;
    --radius-lg: 16px;
    --radius-xl: 24px;

    --bg-glass: rgba(255, 255, 255, 0.72);
    --accent-glow: rgba(59, 130, 246, 0.25);
    
    /* Codeforces Rank Colors */
    --rank-newbie: #808080;
    --rank-pupil: #008000;
    --rank-specialist: #03a89e;
    --rank-expert: #0000ff;
    --rank-candidate-master: #aa00aa;
    --rank-master: #ff8c00;
    --rank-international-master: #ff8c00;
    --rank-grandmaster: #ff0000;
    --rank-international-grandmaster: #ff0000;
    --rank-legendary-grandmaster: #ff0000;
}

[data-theme="dark"] {
    --bg-primary: #080c16;
    --bg-secondary: #1e293b;
    --bg-tertiary: #334155;
    --bg-card: #1e293b;
    --bg-card-hover: #334155;
    
    --text-primary: #f8fafc;
    --text-secondary: #cbd5e1;
    --text-tertiary: #94a3b8;
    --text-muted: #64748b;
    
    --border-color: #334155;
    --border-light: #475569;
    
    --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.3);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.4), 0 2px 4px -1px rgba(0, 0, 0, 0.3);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.4), 0 4px 6px -2px rgba(0, 0, 0, 0.3);
    --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.5), 0 10px 10px -5px rgba(0, 0, 0, 0.4);

    --bg-glass: rgba(15, 22, 41, 0.7);
    --accent-glow: rgba(59, 130, 246, 0.25);
}

/* ===== Base Styles ===== */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    background-color: var(--bg-primary);
    color: var(--text-primary);
    line-height: 1.6;
    min-height: 100vh;
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

[data-theme="dark"] body {
    background-image: radial-gradient(ellipse 80% 60% at 50% -20%, rgba(99, 102, 241, 0.08), transparent);
    background-attachment: fixed;
}

h1, h2, h3 {
    font-family: 'Space Grotesk', sans-serif;
}

.container {
    max-width: 1400px;
    margin: 0 auto;
    padding: 0 24px;
}

.hidden {
    display: none !important;
}

/* ===== Header ===== */
.header {
    background: var(--bg-glass);
    border-bottom: 1px solid var(--border-color);
    position: sticky;
    top: 0;
    z-index: 100;
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

.header::after {
    content: '';
    position: absolute;
    left: 0;
    right: 0;
    bottom: 0;
    height: 2px;
    pointer-events: none;
    background: linear-gradient(90deg, transparent, var(--accent-primary) 25%, var(--accent-secondary) 75%, transparent);
    opacity: 0.4;
}

.header-content {
    display: flex;
    justify-content: space-between;
    align-items: center;
    height: 70px;
}

.header-left {
    display: flex;
    align-items: center;
    gap: 8px;
}

.back-link,
.home-link {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 40px;
    height: 40px;
    border-radius: 50%;
    color: var(--text-secondary);
    text-decoration: none;
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

.back-link:hover,
.home-link:hover {
    background: var(--bg-tertiary);
    color: var(--accent-primary);
}

.logo {
    display: flex;
    align-items: center;
    gap: 12px;
}

.logo-icon {
    width: 36px;
    height: 36px;
    color: var(--accent-primary);
}

.logo h1 {
    font-size: 1.5rem;
    font-weight: 700;
    background: var(--accent-gradient);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.theme-toggle {
    width: 44px;
    height: 44px;
    border-radius: 50%;
    border: 2px solid var(--border-color);
    background: var(--bg-tertiary);
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

.theme-toggle:hover {
    border-color: var(--accent-primary);
    transform: rotate(15deg);
}

.theme-toggle svg {
    width: 22px;
    height: 22px;
    color: var(--text-secondary);
}

[data-theme="light"] .moon-icon,
[data-theme="dark"] .sun-icon {
    display: none;
}

/* ===== Main Content ===== */
.main {
    padding: 40px 0;
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

@keyframes fadeSlideUp {
    from {
        opacity: 0;
        transform: translateY(16px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.section {
    margin-bottom: 48px;
    animation: fadeSlideUp 0.55s cubic-bezier(0.4, 0, 0.2, 1) both;
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

.section-header {
    margin-bottom: 24px;
}

.section-header h2 {
    font-size: 1.75rem;
    font-weight: 700;
    color: var(--text-primary);
    margin-bottom: 8px;
}

.section-subtitle {
    color: var(--text-tertiary);
    font-size: 0.95rem;
}

/* ===== Search Section ===== */
.search-section {
    margin-bottom: 48px;
}

.search-card {
    background: var(--bg-glass);
    backdrop-filter: blur(16px);
    -webkit-backdrop-filter: blur(16px);
    border-radius: var(--radius-xl);
    padding: 48px;
    text-align: center;
    box-shadow: var(--shadow-lg);
    border: 1px solid var(--border-color);
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

.search-card h2 {
    font-size: 2rem;
    font-weight: 700;
    margin-bottom: 12px;
    background: var(--accent-gradient);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.search-subtitle {
    color: var(--text-tertiary);
    margin-bottom: 32px;
}

.search-form {
    display: flex;
    gap: 16px;
    max-width: 600px;
    margin: 0 auto;
}

.input-wrapper {
    flex: 1;
    position: relative;
}

.search-icon {
    position: absolute;
    left: 16px;
    top: 50%;
    transform: translateY(-50%);
    width: 20px;
    height: 20px;
    color: var(--text-muted);
}

.input-wrapper input {
    width: 100%;
    padding: 16px 16px 16px 48px;
    font-size: 1rem;
    border: 2px solid var(--border-color);
    border-radius: var(--radius-lg);
    background: var(--bg-tertiary);
    color: var(--text-primary);
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

.input-wrapper input:focus {
    outline: none;
    border-color: var(--accent-primary);
    box-shadow: 0 0 0 4px var(--accent-glow);
}

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

.analyze-btn {
    display: flex;
    align-items: center;
    gap: 8px;
    padding: 16px 32px;
    font-size: 1rem;
    font-weight: 600;
    font-family: 'Space Grotesk', sans-serif;
    color: white;
    background: var(--accent-gradient);
    border: none;
    border-radius: var(--radius-lg);
    cursor: pointer;
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

.analyze-btn:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg);
}

.analyze-btn svg {
    width: 20px;
    height: 20px;
}

.loading-indicator {
    display: none;
    align-items: center;
    justify-content: center;
    gap: 12px;
    margin-top: 24px;
    color: var(--text-secondary);
}

.loading-indicator.active {
    display: flex;
}

.spinner {
    width: 24px;
    height: 24px;
    border: 3px solid var(--border-color);
    border-top-color: var(--accent-primary);
    border-radius: 50%;
    animation: spin 1s linear infinite;
}

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

.error-message {
    display: none;
    margin-top: 24px;
    padding: 16px;
    background: rgba(239, 68, 68, 0.1);
    border: 1px solid var(--danger);
    border-radius: var(--radius-md);
    color: var(--danger);
}

.error-message.active {
    display: block;
}

/* ===== Profile Section ===== */
.profile-card {
    display: flex;
    gap: 32px;
    background: var(--bg-glass);
    backdrop-filter: blur(16px);
    -webkit-backdrop-filter: blur(16px);
    border-radius: var(--radius-xl);
    padding: 32px;
    box-shadow: var(--shadow-lg);
    border: 1px solid var(--border-color);
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

.profile-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-xl);
}

.profile-avatar {
    flex-shrink: 0;
}

.profile-avatar img {
    width: 140px;
    height: 140px;
    border-radius: var(--radius-lg);
    border: 4px solid var(--accent-primary);
    object-fit: cover;
}

.profile-info {
    flex: 1;
}

.profile-info h3 {
    font-size: 1.75rem;
    font-weight: 700;
    margin-bottom: 8px;
}

.profile-rank {
    display: inline-block;
    padding: 6px 16px;
    border-radius: 20px;
    font-weight: 600;
    font-size: 0.9rem;
    margin-bottom: 20px;
}

.profile-stats {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 24px;
}

.stat-item {
    text-align: center;
    padding: 16px;
    background: var(--bg-tertiary);
    border-radius: var(--radius-md);
    backdrop-filter: blur(16px);
    -webkit-backdrop-filter: blur(16px);
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

.stat-value {
    display: block;
    font-size: 1.75rem;
    font-weight: 700;
    font-family: 'JetBrains Mono', monospace;
    color: var(--accent-primary);
}

.stat-label {
    font-size: 0.85rem;
    color: var(--text-tertiary);
}

/* ===== Daily Problems Section ===== */
.daily-filter {
    display: flex;
    align-items: center;
    gap: 12px;
    margin-bottom: 24px;
    flex-wrap: wrap;
}

.date-input {
    padding: 10px 16px;
    font-size: 0.95rem;
    border: 2px solid var(--border-color);
    border-radius: var(--radius-md);
    background: var(--bg-tertiary);
    color: var(--text-primary);
    cursor: pointer;
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

.date-input:focus {
    outline: none;
    border-color: var(--accent-primary);
    box-shadow: 0 0 0 4px var(--accent-glow);
}

.date-separator {
    color: var(--text-tertiary);
}

.filter-btn, .reset-btn {
    padding: 10px 20px;
    font-size: 0.9rem;
    font-weight: 600;
    border-radius: var(--radius-md);
    cursor: pointer;
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

.filter-btn {
    background: var(--accent-primary);
    color: white;
    border: none;
}

.filter-btn:hover {
    background: var(--accent-secondary);
}

.reset-btn {
    background: transparent;
    color: var(--text-secondary);
    border: 2px solid var(--border-color);
}

.reset-btn:hover {
    border-color: var(--text-secondary);
}

.daily-problems-list {
    max-height: 600px;
    overflow-y: auto;
    padding-right: 8px;
}

.daily-problems-list::-webkit-scrollbar {
    width: 8px;
}

.daily-problems-list::-webkit-scrollbar-track {
    background: var(--bg-tertiary);
    border-radius: 4px;
}

.daily-problems-list::-webkit-scrollbar-thumb {
    background: var(--border-light);
    border-radius: 4px;
}

.daily-problems-list::-webkit-scrollbar-thumb:hover {
    background: var(--text-muted);
}

.day-card {
    background: var(--bg-glass);
    backdrop-filter: blur(16px);
    -webkit-backdrop-filter: blur(16px);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-lg);
    margin-bottom: 16px;
    overflow: hidden;
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

.day-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 16px 20px;
    background: var(--bg-tertiary);
    cursor: pointer;
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

.day-header:hover {
    background: var(--bg-card-hover);
}

.day-date {
    font-weight: 600;
    color: var(--text-primary);
}

.day-count {
    display: flex;
    align-items: center;
    gap: 8px;
}

.day-count span {
    background: var(--accent-primary);
    color: white;
    padding: 4px 12px;
    border-radius: 20px;
    font-size: 0.85rem;
    font-weight: 600;
}

.day-content {
    padding: 16px 20px;
    display: none;
}

.day-content.expanded {
    display: block;
}

.rating-group {
    margin-bottom: 16px;
}

.rating-group:last-child {
    margin-bottom: 0;
}

.rating-label {
    display: inline-block;
    padding: 4px 12px;
    border-radius: 6px;
    font-size: 0.8rem;
    font-weight: 600;
    margin-bottom: 8px;
}

.problem-list {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
}

.problem-chip {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    padding: 6px 12px;
    background: var(--bg-tertiary);
    border-radius: var(--radius-sm);
    font-size: 0.85rem;
    color: var(--text-secondary);
    text-decoration: none;
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

.problem-chip:hover {
    background: var(--accent-primary);
    color: white;
}

/* ===== Topic Distribution Section ===== */
.topic-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(250px, 1fr));
    gap: 16px;
    margin-bottom: 32px;
}

.topic-card {
    background: var(--bg-glass);
    backdrop-filter: blur(16px);
    -webkit-backdrop-filter: blur(16px);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    padding: 20px;
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

.topic-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-md);
}

.topic-name {
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: 12px;
}

.topic-bar {
    height: 8px;
    background: var(--bg-tertiary);
    border-radius: 4px;
    overflow: hidden;
    margin-bottom: 8px;
}

.topic-bar-fill {
    height: 100%;
    background: var(--accent-gradient);
    border-radius: 4px;
    transition: width 0.5s cubic-bezier(0.4, 0, 0.2, 1);
}

.topic-count {
    font-size: 0.85rem;
    color: var(--text-tertiary);
}

.topic-chart {
    background: var(--bg-glass);
    backdrop-filter: blur(16px);
    -webkit-backdrop-filter: blur(16px);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-lg);
    padding: 24px;
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

/* ===== Analytics Charts Section ===== */
.date-filter-section {
    display: flex;
    align-items: center;
    gap: 12px;
    margin-bottom: 24px;
    flex-wrap: wrap;
    padding: 16px;
    background: var(--bg-glass);
    backdrop-filter: blur(16px);
    -webkit-backdrop-filter: blur(16px);
    border-radius: var(--radius-md);
    border: 1px solid var(--border-color);
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

.date-filter-section label {
    font-weight: 600;
    color: var(--text-secondary);
}

.charts-grid {
    display: grid;
    grid-template-columns: 1fr;
    gap: 24px;
}

.chart-card {
    position: relative;
    background: var(--bg-glass);
    backdrop-filter: blur(16px);
    -webkit-backdrop-filter: blur(16px);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-lg);
    padding: 24px;
    overflow: hidden;
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

.chart-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 3px;
    background: linear-gradient(90deg, var(--accent-primary), var(--accent-secondary));
    opacity: 0;
    transition: opacity 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    pointer-events: none;
    z-index: 1;
}

.chart-card:hover::before {
    opacity: 0.45;
}

.chart-header {
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
    margin-bottom: 8px;
}

.chart-stats-group {
    display: flex;
    gap: 12px;
}

.chart-stat {
    display: flex;
    flex-direction: column;
    align-items: center;
    padding: 12px 20px;
    background: var(--bg-tertiary);
    border-radius: var(--radius-md);
    min-width: 90px;
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

.chart-stat.highlight {
    background: linear-gradient(135deg, rgba(16, 185, 129, 0.15) 0%, rgba(5, 150, 105, 0.15) 100%);
    border: 1px solid rgba(16, 185, 129, 0.3);
}

.chart-stat.highlight .chart-stat-value {
    color: var(--success);
}

.chart-stat-value {
    font-size: 1.35rem;
    font-weight: 700;
    font-family: 'JetBrains Mono', monospace;
    color: var(--accent-primary);
}

.chart-stat-label {
    font-size: 0.75rem;
    color: var(--text-tertiary);
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.chart-card h3 {
    font-size: 1.25rem;
    font-weight: 600;
    margin-bottom: 8px;
}

.chart-description {
    font-size: 0.9rem;
    color: var(--text-tertiary);
    margin-bottom: 16px;
}

.formula-display {
    background: var(--bg-tertiary);
    border-radius: var(--radius-md);
    padding: 12px 16px;
    margin-bottom: 16px;
    overflow-x: auto;
}

.formula-display code {
    font-family: 'Fira Code', monospace;
    font-size: 0.9rem;
    color: var(--accent-primary);
}

.chart-wrapper {
    position: relative;
    height: 350px;
}

/* ===== Rating Bars Section ===== */
.rating-bars-container {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(180px, 1fr));
    gap: 16px;
}

.rating-bar-item {
    background: var(--bg-glass);
    backdrop-filter: blur(16px);
    -webkit-backdrop-filter: blur(16px);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    padding: 16px;
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

.rating-bar-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 12px;
}

.rating-bar-label {
    font-weight: 700;
    font-size: 1.1rem;
}

.rating-bar-count {
    font-size: 0.9rem;
    color: var(--text-tertiary);
}

.rating-bar-track {
    height: 24px;
    background: var(--bg-tertiary);
    border-radius: var(--radius-sm);
    overflow: hidden;
    position: relative;
}

.rating-bar-fill {
    height: 100%;
    transition: width 0.5s cubic-bezier(0.4, 0, 0.2, 1);
    display: flex;
    align-items: center;
    justify-content: flex-end;
    padding-right: 8px;
    min-width: 0;
}

.rating-bar-fill.complete {
    background: linear-gradient(135deg, #10b981 0%, #059669 100%);
}

.rating-bar-fill.incomplete {
    background: linear-gradient(135deg, #3b82f6 0%, #6366f1 100%);
}

.rating-bar-percent {
    font-size: 0.75rem;
    font-weight: 600;
    color: white;
}

/* ===== Mentoring Section ===== */
.mentoring-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 24px;
    margin-bottom: 32px;
}

.mentoring-card {
    background: var(--bg-glass);
    backdrop-filter: blur(16px);
    -webkit-backdrop-filter: blur(16px);
    border: 1px solid var(--border-color);
    border-left-width: 4px;
    border-radius: var(--radius-lg);
    overflow: hidden;
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

.mentoring-card.strengths {
    border-left-color: var(--success);
}

.mentoring-card.improvements {
    border-left-color: var(--warning);
}

.mentoring-card.advice {
    border-left-color: var(--accent-primary);
}

.mentoring-card.priorities {
    border-left-color: #8b5cf6;
}

.mentoring-card .card-header {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 20px;
    border-bottom: 1px solid var(--border-color);
}

.mentoring-card .card-header svg {
    width: 24px;
    height: 24px;
}

.mentoring-card.strengths .card-header {
    background: linear-gradient(135deg, rgba(16, 185, 129, 0.1) 0%, rgba(5, 150, 105, 0.1) 100%);
}

.mentoring-card.strengths .card-header svg {
    color: var(--success);
}

.mentoring-card.improvements .card-header {
    background: linear-gradient(135deg, rgba(245, 158, 11, 0.1) 0%, rgba(217, 119, 6, 0.1) 100%);
}

.mentoring-card.improvements .card-header svg {
    color: var(--warning);
}

.mentoring-card.advice .card-header {
    background: linear-gradient(135deg, rgba(59, 130, 246, 0.1) 0%, rgba(99, 102, 241, 0.1) 100%);
}

.mentoring-card.advice .card-header svg {
    color: var(--accent-primary);
}

.mentoring-card.priorities .card-header {
    background: linear-gradient(135deg, rgba(139, 92, 246, 0.1) 0%, rgba(124, 58, 237, 0.1) 100%);
}

.mentoring-card.priorities .card-header svg {
    color: #8b5cf6;
}

.mentoring-card .card-header h3 {
    font-size: 1.1rem;
    font-weight: 600;
}

.mentoring-card .card-content {
    padding: 20px;
    max-height: 300px;
    overflow-y: auto;
}

.mentor-item {
    display: flex;
    align-items: flex-start;
    gap: 12px;
    padding: 12px;
    background: var(--bg-tertiary);
    border-radius: var(--radius-md);
    margin-bottom: 10px;
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

.mentor-item:last-child {
    margin-bottom: 0;
}

.mentor-item-icon {
    flex-shrink: 0;
    width: 32px;
    height: 32px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 700;
    font-size: 0.9rem;
}

.mentor-item-content {
    flex: 1;
}

.mentor-item-title {
    font-weight: 600;
    margin-bottom: 4px;
}

.mentor-item-desc {
    font-size: 0.9rem;
    color: var(--text-tertiary);
}

/* ===== Suggestions Section ===== */
.suggestions-section {
    background: var(--bg-glass);
    backdrop-filter: blur(16px);
    -webkit-backdrop-filter: blur(16px);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-lg);
    padding: 24px;
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

.suggestions-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 20px;
}

.suggestions-header h3 {
    font-size: 1.25rem;
    font-weight: 600;
}

.refresh-btn {
    display: flex;
    align-items: center;
    gap: 8px;
    padding: 10px 20px;
    background: var(--accent-gradient);
    color: white;
    border: none;
    border-radius: var(--radius-md);
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

.refresh-btn:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
}

.refresh-btn svg {
    width: 18px;
    height: 18px;
}

.suggestions-list {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
    gap: 16px;
}

.suggestion-card {
    background: var(--bg-tertiary);
    border-radius: var(--radius-md);
    padding: 20px;
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

.suggestion-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-md);
}

.suggestion-header {
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
    margin-bottom: 12px;
}

.suggestion-name {
    font-weight: 600;
    color: var(--text-primary);
}

.suggestion-rating {
    padding: 4px 10px;
    border-radius: 6px;
    font-size: 0.8rem;
    font-weight: 600;
}

.suggestion-tags {
    display: flex;
    flex-wrap: wrap;
    gap: 6px;
    margin-bottom: 12px;
}

.suggestion-tag {
    padding: 3px 8px;
    background: var(--bg-card);
    border-radius: 4px;
    font-size: 0.75rem;
    color: var(--text-tertiary);
}

.suggestion-link {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    color: var(--accent-primary);
    text-decoration: none;
    font-size: 0.9rem;
    font-weight: 500;
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

.suggestion-link:hover {
    text-decoration: underline;
}

/* ===== Verdict Section ===== */
.verdict-container {
    background: var(--bg-glass);
    backdrop-filter: blur(16px);
    -webkit-backdrop-filter: blur(16px);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-xl);
    padding: 40px;
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

.verdict-comparison {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 40px;
    margin-bottom: 40px;
}

.verdict-card {
    flex: 1;
    max-width: 350px;
    text-align: center;
    padding: 32px;
    border-radius: var(--radius-lg);
    border: 2px solid var(--border-color);
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

.verdict-card.virtual-rank {
    background: linear-gradient(135deg, rgba(99, 102, 241, 0.1) 0%, rgba(139, 92, 246, 0.1) 100%);
    border-color: #6366f1;
}

.verdict-card.actual-rank {
    background: linear-gradient(135deg, rgba(16, 185, 129, 0.1) 0%, rgba(5, 150, 105, 0.1) 100%);
    border-color: #10b981;
}

.verdict-label {
    font-size: 0.9rem;
    color: var(--text-tertiary);
    text-transform: uppercase;
    letter-spacing: 1px;
    margin-bottom: 16px;
}

.verdict-rank {
    font-size: 2rem;
    font-weight: 700;
    margin-bottom: 12px;
}

.verdict-details {
    font-size: 0.95rem;
    color: var(--text-secondary);
}

.verdict-vs {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--text-muted);
}

.verdict-analysis {
    background: var(--bg-tertiary);
    border-radius: var(--radius-md);
    padding: 24px;
    margin-bottom: 32px;
}

.verdict-analysis p {
    margin-bottom: 12px;
    line-height: 1.8;
}

.verdict-analysis p:last-child {
    margin-bottom: 0;
}

.final-recommendations {
    border-top: 1px solid var(--border-color);
    padding-top: 24px;
}

.final-recommendations h3 {
    font-size: 1.25rem;
    margin-bottom: 16px;
}

.recommendation-item {
    display: flex;
    align-items: flex-start;
    gap: 12px;
    padding: 16px;
    background: var(--bg-tertiary);
    border-radius: var(--radius-md);
    margin-bottom: 12px;
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

.recommendation-item:last-child {
    margin-bottom: 0;
}

.recommendation-number {
    flex-shrink: 0;
    width: 28px;
    height: 28px;
    background: var(--accent-gradient);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    font-weight: 700;
    font-size: 0.85rem;
}

.recommendation-text {
    flex: 1;
    color: var(--text-secondary);
    line-height: 1.6;
}

/* ===== Footer ===== */
.footer {
    background: var(--bg-glass);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    border-top: 1px solid var(--border-color);
    padding: 24px 0;
    text-align: center;
    color: var(--text-tertiary);
    font-size: 0.9rem;
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

/* ===== Responsive Design ===== */
@media (max-width: 1024px) {
    .mentoring-grid {
        grid-template-columns: 1fr;
    }
    
    .profile-stats {
        grid-template-columns: repeat(2, 1fr);
    }
    
    .verdict-comparison {
        flex-direction: column;
        gap: 24px;
    }
    
    .verdict-card {
        max-width: 100%;
        width: 100%;
    }
    
    .verdict-vs {
        transform: rotate(90deg);
    }
}

@media (max-width: 768px) {
    .header-content {
        height: 60px;
    }
    
    .back-link,
    .home-link {
        width: 36px;
        height: 36px;
    }
    
    .logo h1 {
        font-size: 1.25rem;
    }
    
    .logo-icon {
        width: 28px;
        height: 28px;
    }
    
    .main {
        padding: 24px 0;
    }
    
    .section {
        margin-bottom: 32px;
    }
    
    .search-card {
        padding: 32px 20px;
    }
    
    .search-card h2 {
        font-size: 1.5rem;
    }
    
    .search-form {
        flex-direction: column;
    }
    
    .analyze-btn {
        width: 100%;
        justify-content: center;
    }
    
    .profile-card {
        flex-direction: column;
        text-align: center;
        padding: 24px;
        gap: 20px;
    }
    
    .profile-avatar img {
        width: 100px;
        height: 100px;
    }
    
    .profile-info h3 {
        font-size: 1.4rem;
    }
    
    .profile-stats {
        grid-template-columns: repeat(2, 1fr);
    }
    
    .date-filter-section {
        flex-direction: column;
        align-items: stretch;
    }
    
    .daily-filter {
        flex-direction: column;
        align-items: stretch;
    }
    
    .day-header {
        padding: 12px 16px;
    }
    
    .day-date {
        font-size: 0.9rem;
    }
    
    .day-content {
        padding: 12px 16px;
    }
    
    .chart-header {
        flex-direction: column;
        gap: 12px;
    }
    
    .chart-stats-group {
        width: 100%;
        justify-content: center;
    }
    
    .chart-stat {
        min-width: 0;
        flex: 1;
        padding: 10px 12px;
    }
    
    .chart-wrapper {
        height: 280px;
    }
    
    .chart-card {
        padding: 16px;
    }
    
    .rating-bars-container {
        grid-template-columns: 1fr 1fr;
    }
    
    .suggestions-header {
        flex-direction: column;
        gap: 16px;
    }
    
    .refresh-btn {
        width: 100%;
        justify-content: center;
    }
    
    .suggestions-list {
        grid-template-columns: 1fr;
    }
    
    .verdict-container {
        padding: 24px 16px;
    }
    
    .verdict-rank {
        font-size: 1.5rem;
    }
    
    .verdict-details {
        font-size: 0.8rem;
        word-break: break-word;
    }
    
    .verdict-label {
        font-size: 0.8rem;
        letter-spacing: 0.5px;
    }
    
    .verdict-card {
        padding: 24px 16px;
    }
}

@media (max-width: 480px) {
    .container {
        padding: 0 12px;
    }
    
    .header-content {
        height: 52px;
    }
    
    .header-left {
        gap: 4px;
    }
    
    .back-link,
    .home-link {
        width: 32px;
        height: 32px;
    }
    
    .back-link svg,
    .home-link svg {
        width: 16px;
        height: 16px;
    }
    
    .logo {
        gap: 6px;
    }
    
    .logo h1 {
        font-size: 1.05rem;
    }
    
    .logo-icon {
        width: 22px;
        height: 22px;
    }
    
    .theme-toggle {
        width: 36px;
        height: 36px;
    }
    
    .theme-toggle svg {
        width: 18px;
        height: 18px;
    }
    
    .main {
        padding: 16px 0;
    }
    
    .section {
        margin-bottom: 24px;
    }
    
    .section-header h2 {
        font-size: 1.3rem;
    }
    
    .section-subtitle {
        font-size: 0.85rem;
    }
    
    .search-card {
        padding: 24px 16px;
    }
    
    .search-card h2 {
        font-size: 1.3rem;
    }
    
    .search-subtitle {
        font-size: 0.85rem;
        margin-bottom: 20px;
    }
    
    .input-wrapper input {
        padding: 14px 14px 14px 42px;
        font-size: 0.9rem;
    }
    
    .analyze-btn {
        padding: 14px 24px;
    }
    
    .profile-card {
        padding: 20px;
    }
    
    .profile-avatar img {
        width: 80px;
        height: 80px;
    }
    
    .profile-info h3 {
        font-size: 1.2rem;
    }
    
    .profile-rank {
        font-size: 0.8rem;
        padding: 4px 12px;
    }
    
    .profile-stats {
        grid-template-columns: 1fr 1fr;
        gap: 8px;
    }
    
    .stat-item {
        padding: 12px 8px;
    }
    
    .chart-header h3 {
        font-size: 1.05rem;
    }
    
    .chart-description {
        font-size: 0.8rem;
    }
    
    .chart-stat-value {
        font-size: 1.1rem;
    }
    
    .chart-stat-label {
        font-size: 0.65rem;
    }
    
    .chart-wrapper {
        height: 220px;
    }
    
    .formula-display {
        padding: 8px 12px;
    }
    
    .formula-display code {
        font-size: 0.7rem;
    }
    
    .rating-bars-container {
        grid-template-columns: 1fr;
    }
    
    .rating-bar-item {
        padding: 12px;
    }
    
    .topic-grid {
        grid-template-columns: 1fr;
    }
    
    .topic-card {
        padding: 14px;
    }
    
    .topic-chart {
        padding: 12px;
    }
    
    .mentoring-card .card-header {
        padding: 14px;
    }
    
    .mentoring-card .card-header h3 {
        font-size: 0.95rem;
    }
    
    .mentoring-card .card-content {
        padding: 12px;
        max-height: 250px;
    }
    
    .mentor-item {
        padding: 10px;
        gap: 8px;
    }
    
    .mentor-item-icon {
        width: 28px;
        height: 28px;
        font-size: 0.75rem;
    }
    
    .mentor-item-title {
        font-size: 0.9rem;
    }
    
    .mentor-item-desc {
        font-size: 0.8rem;
    }
    
    .suggestions-section {
        padding: 16px;
    }
    
    .suggestion-card {
        padding: 14px;
    }
    
    .suggestion-name {
        font-size: 0.85rem;
    }
    
    .verdict-container {
        padding: 16px 12px;
    }
    
    .verdict-card {
        padding: 16px;
    }
    
    .verdict-rank {
        font-size: 1.2rem;
        word-break: break-word;
    }
    
    .verdict-details {
        font-size: 0.75rem;
    }
    
    .verdict-vs {
        font-size: 1.1rem;
    }
    
    .verdict-analysis {
        padding: 16px;
    }
    
    .verdict-analysis p {
        font-size: 0.9rem;
    }
    
    .final-recommendations h3 {
        font-size: 1.05rem;
    }
    
    .recommendation-item {
        padding: 12px;
        gap: 10px;
    }
    
    .recommendation-number {
        width: 24px;
        height: 24px;
        font-size: 0.75rem;
    }
    
    .recommendation-text {
        font-size: 0.85rem;
    }
    
    .daily-problems-list {
        max-height: 450px;
        padding-right: 4px;
    }
    
    .problem-chip {
        padding: 4px 8px;
        font-size: 0.8rem;
    }
    
    .filter-btn, .reset-btn {
        padding: 10px 16px;
        font-size: 0.85rem;
    }
}

/* ===== Rating Color Classes ===== */
.rating-800 { color: #808080; background: rgba(128, 128, 128, 0.2); }
.rating-900 { color: #808080; background: rgba(128, 128, 128, 0.2); }
.rating-1000 { color: #808080; background: rgba(128, 128, 128, 0.2); }
.rating-1100 { color: #808080; background: rgba(128, 128, 128, 0.2); }
.rating-1200 { color: #008000; background: rgba(0, 128, 0, 0.2); }
.rating-1300 { color: #008000; background: rgba(0, 128, 0, 0.2); }
.rating-1400 { color: #03a89e; background: rgba(3, 168, 158, 0.2); }
.rating-1500 { color: #03a89e; background: rgba(3, 168, 158, 0.2); }
.rating-1600 { color: #0000ff; background: rgba(0, 0, 255, 0.2); }
.rating-1700 { color: #0000ff; background: rgba(0, 0, 255, 0.2); }
.rating-1800 { color: #0000ff; background: rgba(0, 0, 255, 0.2); }
.rating-1900 { color: #aa00aa; background: rgba(170, 0, 170, 0.2); }
.rating-2000 { color: #aa00aa; background: rgba(170, 0, 170, 0.2); }
.rating-2100 { color: #ff8c00; background: rgba(255, 140, 0, 0.2); }
.rating-2200 { color: #ff8c00; background: rgba(255, 140, 0, 0.2); }
.rating-2300 { color: #ff8c00; background: rgba(255, 140, 0, 0.2); }
.rating-2400 { color: #ff0000; background: rgba(255, 0, 0, 0.2); }

/* Rank color backgrounds */
.rank-newbie { background: var(--rank-newbie); color: white; }
.rank-pupil { background: var(--rank-pupil); color: white; }
.rank-specialist { background: var(--rank-specialist); color: white; }
.rank-expert { background: var(--rank-expert); color: white; }
.rank-candidate-master { background: var(--rank-candidate-master); color: white; }
.rank-master { background: var(--rank-master); color: white; }
.rank-international-master { background: var(--rank-international-master); color: white; }
.rank-grandmaster { background: var(--rank-grandmaster); color: white; }
.rank-international-grandmaster { background: var(--rank-international-grandmaster); color: white; }
.rank-legendary-grandmaster { background: var(--rank-legendary-grandmaster); color: white; }

/* ===== Chart.js Theme Overrides ===== */
.chart-wrapper canvas {
    max-height: 350px;
}