/* ==========================================================================
   Pershi Ledi UGC Bot - Premium Mini App Styles
   Brand Colors: Primary #0d6eff, Secondary #4f8fff
   ========================================================================== */

/* CSS Variables */
:root {
    /* Brand Colors */
    --color-primary: #0d6eff;
    --color-primary-light: #4f8fff;
    --color-primary-dark: #0a5ad4;
    --color-primary-glow: rgba(13, 110, 255, 0.3);

    /* Gradients */
    --gradient-primary: linear-gradient(135deg, #0d6eff 0%, #4f8fff 100%);
    --gradient-header: linear-gradient(180deg, #0d6eff 0%, #0a5ad4 100%);
    --gradient-card: linear-gradient(145deg, rgba(13, 110, 255, 0.15) 0%, rgba(79, 143, 255, 0.05) 100%);
    --gradient-glow: radial-gradient(ellipse at center, rgba(13, 110, 255, 0.2) 0%, transparent 70%);

    /* Base Colors */
    --color-white: #ffffff;
    --color-background: #f5f7fa;
    --color-surface: #ffffff;
    --color-surface-elevated: #ffffff;

    /* Text Colors */
    --color-text-primary: #1a1d21;
    --color-text-secondary: #6b7280;
    --color-text-muted: #9ca3af;
    --color-text-inverse: #ffffff;

    /* Semantic Colors */
    --color-success: #10b981;
    --color-success-light: rgba(16, 185, 129, 0.1);
    --color-error: #ef4444;
    --color-error-light: rgba(239, 68, 68, 0.1);
    --color-warning: #f59e0b;

    /* Borders & Shadows */
    --border-color: rgba(0, 0, 0, 0.08);
    --border-color-light: rgba(0, 0, 0, 0.04);
    --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 12px rgba(0, 0, 0, 0.08);
    --shadow-lg: 0 8px 24px rgba(0, 0, 0, 0.12);
    --shadow-primary: 0 4px 20px rgba(13, 110, 255, 0.25);
    --shadow-primary-lg: 0 8px 32px rgba(13, 110, 255, 0.35);

    /* Spacing */
    --spacing-xs: 4px;
    --spacing-sm: 8px;
    --spacing-md: 16px;
    --spacing-lg: 24px;
    --spacing-xl: 32px;

    /* Border Radius */
    --radius-sm: 8px;
    --radius-md: 12px;
    --radius-lg: 16px;
    --radius-xl: 24px;
    --radius-full: 9999px;

    /* Transitions */
    --transition-fast: 150ms ease;
    --transition-base: 250ms ease;
    --transition-slow: 350ms ease;
    --transition-spring: 400ms cubic-bezier(0.34, 1.56, 0.64, 1);

    /* Layout */
    --header-height: 80px;
    --nav-height: 70px;
    --safe-area-bottom: env(safe-area-inset-bottom, 0px);
}

/* Reset & Base */
*, *::before, *::after {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html {
    font-size: 16px;
    -webkit-text-size-adjust: 100%;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'SF Pro Display', 'Segoe UI', Roboto, Oxygen, Ubuntu, sans-serif;
    background: var(--color-background);
    color: var(--color-text-primary);
    line-height: 1.5;
    min-height: 100vh;
    overflow-x: hidden;
    -webkit-user-select: none;
    user-select: none;
    -webkit-tap-highlight-color: transparent;
}

/* App Container */
.app {
    display: flex;
    flex-direction: column;
    min-height: 100vh;
    max-width: 480px;
    margin: 0 auto;
    background: var(--color-background);
    position: relative;
}

/* ==========================================================================
   Header
   ========================================================================== */
.header {
    background: var(--gradient-header);
    padding: var(--spacing-lg) var(--spacing-md);
    padding-top: calc(var(--spacing-lg) + env(safe-area-inset-top, 0px));
    position: sticky;
    top: 0;
    z-index: 100;
}

.header-content {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: var(--spacing-md);
}

.logo {
    display: flex;
    align-items: center;
    justify-content: center;
}

.logo svg {
    height: 36px;
    width: auto;
}

.header-title {
    font-size: 20px;
    font-weight: 700;
    color: var(--color-white);
    letter-spacing: -0.3px;
}

/* ==========================================================================
   Main Content
   ========================================================================== */
.main-content {
    flex: 1;
    padding: var(--spacing-md);
    padding-bottom: calc(var(--nav-height) + var(--spacing-lg) + var(--safe-area-bottom));
    overflow-y: auto;
}

.tab-content {
    display: none;
    animation: fadeIn 0.3s ease;
}

.tab-content.active {
    display: block;
}

@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(8px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* ==========================================================================
   Marathon Header Section
   ========================================================================== */
.marathon-header-section {
    background: var(--gradient-primary);
    border-radius: var(--radius-lg);
    padding: var(--spacing-md) var(--spacing-lg);
    margin-bottom: var(--spacing-md);
    box-shadow: var(--shadow-primary);
}

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

.marathon-label {
    font-size: 18px;
    font-weight: 700;
    color: var(--color-white);
}

.marathon-status {
    display: inline-flex;
    align-items: center;
    padding: var(--spacing-xs) var(--spacing-md);
    background: rgba(255, 255, 255, 0.2);
    backdrop-filter: blur(8px);
    border-radius: var(--radius-full);
    font-size: 13px;
    font-weight: 500;
    color: var(--color-white);
}

.section-header {
    margin-bottom: var(--spacing-md);
}

.section-title {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    font-size: 16px;
    font-weight: 600;
    color: var(--color-text-primary);
}

.section-title svg {
    color: var(--color-primary);
}

/* ==========================================================================
   Masterclass Section (Phase 2)
   ========================================================================== */
.masterclass-section {
    background: linear-gradient(145deg, rgba(147, 51, 234, 0.15) 0%, rgba(79, 143, 255, 0.1) 100%);
    border: 1px solid rgba(147, 51, 234, 0.2);
    border-radius: var(--radius-lg);
    padding: var(--spacing-lg);
    margin-bottom: var(--spacing-md);
}

.masterclass-header {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    font-size: 18px;
    font-weight: 700;
    color: var(--color-text-primary);
    margin-bottom: var(--spacing-sm);
}

.masterclass-icon {
    font-size: 24px;
}

.masterclass-title {
    font-size: 14px;
    color: var(--color-text-secondary);
    margin-bottom: var(--spacing-md);
}

.video-container {
    position: relative;
    width: 100%;
    padding-bottom: 56.25%; /* 16:9 aspect ratio */
    border-radius: var(--radius-md);
    overflow: hidden;
    background: var(--color-text-primary);
}

.video-container iframe {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    border: none;
    border-radius: var(--radius-md);
}

/* ==========================================================================
   Checklist Section (Phase 2)
   ========================================================================== */
.checklist-section {
    background: var(--color-surface);
    border-radius: var(--radius-lg);
    padding: var(--spacing-lg);
    margin-bottom: var(--spacing-md);
    box-shadow: var(--shadow-sm);
}

.checklist-header {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    font-size: 18px;
    font-weight: 700;
    color: var(--color-text-primary);
    margin-bottom: var(--spacing-xs);
}

.checklist-icon {
    font-size: 24px;
}

.checklist-description {
    font-size: 14px;
    color: var(--color-text-secondary);
    margin-bottom: var(--spacing-md);
}

.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: var(--spacing-sm);
    padding: var(--spacing-md) var(--spacing-lg);
    font-size: 15px;
    font-weight: 600;
    font-family: inherit;
    text-decoration: none;
    border-radius: var(--radius-md);
    cursor: pointer;
    transition: all var(--transition-base);
}

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

.btn-secondary:hover {
    background: var(--gradient-card);
}

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

/* ==========================================================================
   Materials Tab (Phase 2)
   ========================================================================== */
.materials-header {
    text-align: center;
    margin-bottom: var(--spacing-lg);
}

.materials-card {
    background: var(--color-surface);
    border-radius: var(--radius-lg);
    padding: var(--spacing-lg);
    margin-bottom: var(--spacing-md);
    box-shadow: var(--shadow-sm);
}

.materials-card-header {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    margin-bottom: var(--spacing-md);
}

.materials-card-header h3 {
    margin: 0;
    font-size: 1.1rem;
    font-weight: 600;
}

.materials-icon {
    font-size: 1.5rem;
}

.materials-title {
    color: var(--color-text-secondary);
    margin-bottom: var(--spacing-md);
}

.materials-card .video-container {
    margin-top: var(--spacing-md);
}

.materials-card .btn-block {
    width: 100%;
    text-align: center;
    margin-top: var(--spacing-md);
}

.checklist-description {
    color: var(--color-text-secondary);
    margin-bottom: var(--spacing-sm);
}

/* ==========================================================================
   Prizes Banner (Phase 2)
   ========================================================================== */
.prizes-banner {
    margin-bottom: var(--spacing-lg);
    border-radius: var(--radius-lg);
    overflow: hidden;
    box-shadow: var(--shadow-md);
}

.prizes-banner img {
    width: 100%;
    height: auto;
    display: block;
    border-radius: var(--radius-lg);
}

/* ==========================================================================
   Submission Form Section
   ========================================================================== */
.submission-section {
    background: var(--color-surface);
    border-radius: var(--radius-lg);
    padding: var(--spacing-md);
    box-shadow: var(--shadow-sm);
}

.submission-form {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-md);
}

.form-group {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-xs);
}

.form-label {
    font-size: 14px;
    font-weight: 500;
    color: var(--color-text-primary);
}

.input-wrapper,
.textarea-wrapper {
    position: relative;
}

.input-icon {
    position: absolute;
    left: var(--spacing-md);
    top: 50%;
    transform: translateY(-50%);
    color: var(--color-text-muted);
    display: flex;
    align-items: center;
    pointer-events: none;
    transition: color var(--transition-fast);
}

.form-input,
.form-textarea {
    width: 100%;
    padding: var(--spacing-md);
    font-size: 16px;
    font-family: inherit;
    color: var(--color-text-primary);
    background: var(--color-background);
    border: 2px solid transparent;
    border-radius: var(--radius-md);
    outline: none;
    transition: all var(--transition-fast);
    -webkit-user-select: text;
    user-select: text;
}

.form-input {
    padding-left: 48px;
}

.form-input:focus,
.form-textarea:focus {
    background: var(--color-surface);
    border-color: var(--color-primary);
    box-shadow: 0 0 0 4px var(--color-primary-glow);
}

.form-input:focus + .input-icon,
.input-wrapper:focus-within .input-icon {
    color: var(--color-primary);
}

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

.form-input.error,
.form-textarea.error {
    border-color: var(--color-error);
    background: var(--color-error-light);
}

.form-error {
    font-size: 12px;
    color: var(--color-error);
    min-height: 18px;
    padding-left: var(--spacing-xs);
}

.form-textarea {
    min-height: 100px;
    max-height: 200px;
    resize: vertical;
    line-height: 1.5;
}

.char-counter {
    position: absolute;
    bottom: var(--spacing-sm);
    right: var(--spacing-sm);
    font-size: 11px;
    color: var(--color-text-muted);
    background: var(--color-background);
    padding: 2px 6px;
    border-radius: var(--radius-sm);
}

/* Submit Button */
.submit-btn {
    position: relative;
    display: flex;
    align-items: center;
    justify-content: center;
    width: 100%;
    padding: var(--spacing-md) var(--spacing-lg);
    font-size: 16px;
    font-weight: 600;
    font-family: inherit;
    color: var(--color-white);
    background: var(--gradient-primary);
    border: none;
    border-radius: var(--radius-md);
    cursor: pointer;
    overflow: hidden;
    transition: all var(--transition-base);
    box-shadow: var(--shadow-primary);
}

.submit-btn:hover:not(:disabled) {
    transform: translateY(-2px);
    box-shadow: var(--shadow-primary-lg);
}

.submit-btn:active:not(:disabled) {
    transform: translateY(0) scale(0.98);
}

.submit-btn:disabled {
    opacity: 0.6;
    cursor: not-allowed;
    transform: none;
}

.btn-content {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: var(--spacing-sm);
    transition: opacity var(--transition-fast);
}

.btn-icon {
    transition: transform var(--transition-fast);
}

.submit-btn:hover:not(:disabled) .btn-icon {
    transform: translateX(2px) translateY(-2px);
}

.btn-loader {
    position: absolute;
    width: 24px;
    height: 24px;
    border: 3px solid rgba(255, 255, 255, 0.3);
    border-top-color: var(--color-white);
    border-radius: 50%;
    opacity: 0;
    animation: spin 0.8s linear infinite;
    transition: opacity var(--transition-fast);
}

.submit-btn.loading .btn-content {
    opacity: 0;
}

.submit-btn.loading .btn-loader {
    opacity: 1;
}

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

/* ==========================================================================
   Bottom Navigation
   ========================================================================== */
.bottom-nav {
    position: fixed;
    bottom: 0;
    left: 50%;
    transform: translateX(-50%);
    width: 100%;
    max-width: 480px;
    background: var(--color-surface);
    border-top: 1px solid var(--border-color);
    display: flex;
    justify-content: space-around;
    padding: var(--spacing-sm) var(--spacing-md);
    padding-bottom: calc(var(--spacing-sm) + var(--safe-area-bottom));
    z-index: 100;
    box-shadow: 0 -4px 20px rgba(0, 0, 0, 0.05);
}

.nav-item {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 4px;
    padding: var(--spacing-sm) var(--spacing-md);
    background: none;
    border: none;
    font-family: inherit;
    cursor: pointer;
    transition: all var(--transition-fast);
    border-radius: var(--radius-md);
    -webkit-tap-highlight-color: transparent;
}

.nav-icon {
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--color-text-muted);
    transition: all var(--transition-fast);
}

.nav-label {
    font-size: 11px;
    font-weight: 500;
    color: var(--color-text-muted);
    transition: color var(--transition-fast);
}

.nav-item.active {
    background: var(--gradient-card);
}

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

.nav-item.active .nav-label {
    color: var(--color-primary);
    font-weight: 600;
}

.nav-item:active {
    transform: scale(0.95);
}

/* ==========================================================================
   Submissions Tab
   ========================================================================== */
.submissions-header,
.leaderboard-header {
    text-align: center;
    margin-bottom: var(--spacing-lg);
}

.page-title {
    font-size: 24px;
    font-weight: 700;
    color: var(--color-text-primary);
    margin-bottom: var(--spacing-xs);
}

.page-subtitle {
    font-size: 14px;
    color: var(--color-text-secondary);
}

/* My Stats Section */
.my-stats {
    display: flex;
    align-items: flex-start;
    gap: var(--spacing-md);
    background: var(--gradient-card);
    border: 1px solid rgba(13, 110, 255, 0.2);
    border-radius: var(--radius-lg);
    padding: var(--spacing-md);
    margin-bottom: var(--spacing-md);
}

.stats-icon {
    font-size: 24px;
}

.stats-content {
    flex: 1;
}

.stats-line {
    font-size: 14px;
    color: var(--color-text-primary);
    margin-bottom: var(--spacing-xs);
}

.stats-line:last-child {
    margin-bottom: 0;
    font-weight: 600;
    color: var(--color-primary);
}

.submissions-list {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-md);
}

.submission-card {
    background: var(--color-surface);
    border-radius: var(--radius-lg);
    padding: var(--spacing-md);
    box-shadow: var(--shadow-sm);
    transition: all var(--transition-base);
}

.submission-card:active {
    transform: scale(0.98);
}

/* Top 2 videos that count for leaderboard - gold highlight */
.submission-card.top-2-video {
    background: linear-gradient(135deg, rgba(255, 215, 0, 0.15) 0%, rgba(255, 193, 7, 0.08) 100%);
    border: 2px solid #ffd700;
    box-shadow: 0 4px 16px rgba(255, 215, 0, 0.25);
}

.submission-card.top-2-video .top-2-badge {
    background: linear-gradient(135deg, #ffd700 0%, #ffb300 100%);
    color: #1a1d21;
    font-weight: 600;
}

.submission-week-badge,
.submission-video-badge {
    display: inline-flex;
    align-items: center;
    padding: 4px 10px;
    background: var(--gradient-card);
    border-radius: var(--radius-full);
    font-size: 12px;
    font-weight: 600;
    color: var(--color-primary);
    margin-bottom: var(--spacing-sm);
}

.submission-url {
    font-size: 14px;
    color: var(--color-primary);
    word-break: break-all;
    margin-bottom: var(--spacing-sm);
}

.submission-date {
    font-size: 12px;
    color: var(--color-text-muted);
}

.submission-status {
    display: inline-flex;
    align-items: center;
    gap: var(--spacing-xs);
    padding: 4px 10px;
    border-radius: var(--radius-full);
    font-size: 12px;
    font-weight: 500;
}

.submission-status.pending {
    background: var(--color-warning);
    color: var(--color-white);
}

.submission-status.approved {
    background: var(--color-success);
    color: var(--color-white);
}

.submission-status.rejected {
    background: var(--color-error);
    color: var(--color-white);
}

/* Empty State */
.empty-state {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    padding: var(--spacing-xl);
    text-align: center;
}

.empty-icon {
    color: var(--color-text-muted);
    opacity: 0.5;
    margin-bottom: var(--spacing-md);
}

.empty-state h3 {
    font-size: 18px;
    font-weight: 600;
    color: var(--color-text-primary);
    margin-bottom: var(--spacing-xs);
}

.empty-state p {
    font-size: 14px;
    color: var(--color-text-secondary);
}

/* ==========================================================================
   Leaderboard Tab
   ========================================================================== */
.leaderboard-list {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-sm);
}

.leaderboard-item {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    background: var(--color-surface);
    border-radius: var(--radius-lg);
    padding: var(--spacing-md);
    box-shadow: var(--shadow-sm);
    transition: all var(--transition-base);
    flex-wrap: nowrap;
}

.leaderboard-item.top-3 {
    background: var(--gradient-card);
    border: 1px solid rgba(13, 110, 255, 0.1);
}

.leaderboard-rank {
    width: 36px;
    height: 36px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 14px;
    font-weight: 700;
    border-radius: var(--radius-full);
    background: var(--color-background);
    color: var(--color-text-secondary);
}

.leaderboard-item.top-3 .leaderboard-rank {
    background: var(--gradient-primary);
    color: var(--color-white);
    box-shadow: var(--shadow-primary);
}

.leaderboard-avatar {
    width: 40px;
    height: 40px;
    border-radius: 50%;
    overflow: hidden;
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--gradient-primary);
    color: var(--color-white);
    font-weight: 600;
    font-size: 16px;
    flex-shrink: 0;
}

.leaderboard-avatar img {
    width: 100%;
    height: 100%;
    object-fit: cover;
}

.leaderboard-avatar .avatar-fallback {
    width: 100%;
    height: 100%;
    display: flex;
    align-items: center;
    justify-content: center;
}

.leaderboard-info {
    flex: 1;
}

.leaderboard-name {
    font-size: 15px;
    font-weight: 600;
    color: var(--color-text-primary);
    margin-bottom: 2px;
}

.leaderboard-details {
    font-size: 13px;
    color: var(--color-text-secondary);
}

.leaderboard-stats {
    font-size: 13px;
    color: var(--color-text-secondary);
}

.leaderboard-score {
    font-size: 14px;
    font-weight: 600;
    color: var(--color-primary);
    white-space: nowrap;
    min-width: fit-content;
}

/* Prize badges */
.leaderboard-prize {
    display: flex;
    align-items: center;
    gap: 4px;
    font-weight: 600;
    font-size: 12px;
    padding: 4px 8px;
    border-radius: var(--radius-full);
    white-space: nowrap;
}

.leaderboard-prize.dyson {
    color: #f59e0b;
    background: rgba(245, 158, 11, 0.1);
}

.leaderboard-prize.mystery-box {
    color: #8b5cf6;
    background: rgba(139, 92, 246, 0.1);
}

.leaderboard-prize.ladies {
    color: #10b981;
    background: rgba(16, 185, 129, 0.1);
}

.leaderboard-prize.participation {
    color: var(--color-text-secondary);
    background: var(--color-background);
    font-size: 11px;
}

.leaderboard-prize img {
    width: 24px;
    height: 24px;
    object-fit: contain;
}

.leaderboard-prize .prize-amount {
    font-size: 11px;
    font-weight: 500;
}

/* Rank-specific styling */
.leaderboard-item.rank-1 {
    background: linear-gradient(135deg, rgba(245, 158, 11, 0.15) 0%, rgba(245, 158, 11, 0.05) 100%);
    border: 1px solid rgba(245, 158, 11, 0.3);
}

.leaderboard-item.rank-1 .leaderboard-rank {
    background: linear-gradient(135deg, #f59e0b 0%, #d97706 100%);
    color: var(--color-white);
    box-shadow: 0 4px 12px rgba(245, 158, 11, 0.3);
}

.leaderboard-item.rank-2,
.leaderboard-item.rank-3,
.leaderboard-item.rank-4,
.leaderboard-item.rank-5 {
    background: linear-gradient(135deg, rgba(139, 92, 246, 0.1) 0%, transparent 100%);
    border: 1px solid rgba(139, 92, 246, 0.15);
}

.leaderboard-item.rank-2 .leaderboard-rank,
.leaderboard-item.rank-3 .leaderboard-rank,
.leaderboard-item.rank-4 .leaderboard-rank,
.leaderboard-item.rank-5 .leaderboard-rank {
    background: linear-gradient(135deg, #8b5cf6 0%, #7c3aed 100%);
    color: var(--color-white);
    box-shadow: 0 4px 12px rgba(139, 92, 246, 0.25);
}

/* Separator for user's own position */
.leaderboard-separator {
    text-align: center;
    padding: 8px;
    color: var(--color-text-secondary);
    font-size: 14px;
    letter-spacing: 4px;
}

/* User's own position highlight */
.leaderboard-item.own-position {
    background: linear-gradient(135deg, rgba(79, 143, 255, 0.15) 0%, rgba(79, 143, 255, 0.05) 100%);
    border: 2px solid var(--color-primary);
}

.leaderboard-item.own-position .leaderboard-rank {
    background: var(--gradient-primary);
    color: var(--color-white);
    box-shadow: var(--shadow-primary);
}

.loading-placeholder {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    padding: var(--spacing-xl);
    gap: var(--spacing-md);
}

.loading-spinner {
    width: 32px;
    height: 32px;
    border: 3px solid var(--color-background);
    border-top-color: var(--color-primary);
    border-radius: 50%;
    animation: spin 0.8s linear infinite;
}

.loading-placeholder p {
    font-size: 14px;
    color: var(--color-text-muted);
}

/* ==========================================================================
   Loading Overlay
   ========================================================================== */
.loading-overlay {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(0, 0, 0, 0.5);
    backdrop-filter: blur(4px);
    display: none;
    align-items: center;
    justify-content: center;
    z-index: 1000;
    opacity: 0;
    pointer-events: none;
    transition: opacity var(--transition-base);
}

.loading-overlay.active {
    display: flex;
    opacity: 1;
    pointer-events: auto;
}

.loader-container {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: var(--spacing-md);
}

.loader {
    width: 48px;
    height: 48px;
    border: 4px solid rgba(255, 255, 255, 0.2);
    border-top-color: var(--color-white);
    border-radius: 50%;
    animation: spin 0.8s linear infinite;
}

.loader-text {
    font-size: 14px;
    color: var(--color-white);
    font-weight: 500;
}

/* ==========================================================================
   Toast Notification
   ========================================================================== */
.toast {
    position: fixed;
    bottom: calc(var(--nav-height) + var(--spacing-lg) + var(--safe-area-bottom));
    left: 50%;
    transform: translateX(-50%) translateY(100px);
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    background: var(--color-text-primary);
    color: var(--color-white);
    padding: var(--spacing-md) var(--spacing-lg);
    border-radius: var(--radius-lg);
    font-size: 14px;
    font-weight: 500;
    box-shadow: var(--shadow-lg);
    z-index: 1001;
    opacity: 0;
    pointer-events: none;
    transition: all var(--transition-spring);
    max-width: calc(100% - var(--spacing-xl));
}

.toast.show {
    transform: translateX(-50%) translateY(0);
    opacity: 1;
    pointer-events: auto;
}

.toast.success {
    background: var(--color-success);
}

.toast.error {
    background: var(--color-error);
}

.toast-icon {
    display: flex;
    align-items: center;
}

/* ==========================================================================
   Utility Classes
   ========================================================================== */
.visually-hidden {
    position: absolute;
    width: 1px;
    height: 1px;
    padding: 0;
    margin: -1px;
    overflow: hidden;
    clip: rect(0, 0, 0, 0);
    white-space: nowrap;
    border: 0;
}

/* ==========================================================================
   Responsive Adjustments
   ========================================================================== */
@media (max-width: 360px) {
    :root {
        --spacing-md: 12px;
        --spacing-lg: 20px;
    }

    .header-title {
        font-size: 18px;
    }

    .countdown-value {
        font-size: 28px;
    }

    .countdown-separator {
        font-size: 22px;
    }
}

/* Dark Mode Support (via Telegram Theme) */
@media (prefers-color-scheme: dark) {
    :root {
        --color-background: #1a1d21;
        --color-surface: #2d3139;
        --color-surface-elevated: #363b44;
        --color-text-primary: #ffffff;
        --color-text-secondary: #9ca3af;
        --color-text-muted: #6b7280;
        --border-color: rgba(255, 255, 255, 0.1);
        --border-color-light: rgba(255, 255, 255, 0.05);
    }
}