/* ============================================
           CSS VARIABLES - Easy Theming
           ============================================ */
    :root {
        /* Colors - Dark Theme */
        --bg-primary: #0a0a0f;
        --bg-secondary: #12121a;
        --bg-tertiary: #1a1a25;
        --bg-card: #1e1e2e;
        --bg-hover: #252538;

        /* Accent Colors */
        --accent-primary: #6366f1;
        --accent-secondary: #8b5cf6;
        --accent-gradient: linear-gradient(135deg, #6366f1 0%, #8b5cf6 100%);

        /* Text Colors */
        --text-primary: #f8fafc;
        --text-secondary: #94a3b8;
        --text-muted: #64748b;

        /* Status Colors */
        --success: #22c55e;
        --warning: #f59e0b;
        --error: #ef4444;

        /* Border & Shadows */
        --border-color: #2d2d3d;
        --border-radius-sm: 8px;
        --border-radius-md: 12px;
        --border-radius-lg: 16px;
        --border-radius-xl: 24px;

        /* Typography */
        --font-primary: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
        --font-mono: 'JetBrains Mono', 'SF Mono', monospace;

        /* Spacing */
        --spacing-xs: 0.5rem;
        --spacing-sm: 0.75rem;
        --spacing-md: 1rem;
        --spacing-lg: 1.5rem;
        --spacing-xl: 2rem;
        --spacing-2xl: 3rem;

        /* Transitions */
        --transition-fast: 0.15s ease;
        --transition-normal: 0.25s ease;
    }

    /* ============================================
           RESET & BASE STYLES
           ============================================ */
    *,
    *::before,
    *::after {
        box-sizing: border-box;
        margin: 0;
        padding: 0;
    }

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

    body {
        font-family: var(--font-primary);
        background: var(--bg-primary);
        color: var(--text-primary);
        min-height: 100vh;
        line-height: 1.6;
    }

    /* ============================================
           LAYOUT - Container
           ============================================ */
    .container {
        max-width: 800px;
        margin: 0 auto;
        padding: var(--spacing-lg);
    }

    @media (min-width: 768px) {
        .container {
            padding: var(--spacing-2xl);
        }
    }

    /* ============================================
           HEADER / NAVIGATION
           ============================================ */
    .header {
        display: flex;
        align-items: center;
        justify-content: space-between;
        padding: var(--spacing-md) 0;
        margin-bottom: var(--spacing-2xl);
    }

    .logo {
        display: flex;
        align-items: center;
        gap: var(--spacing-sm);
        font-size: 1.5rem;
        font-weight: 700;
        color: var(--text-primary);
        text-decoration: none;
    }

    .logo-icon {
        width: 36px;
        height: 36px;
        background: var(--accent-gradient);
        border-radius: var(--border-radius-md);
        display: flex;
        align-items: center;
        justify-content: center;
        font-size: 1.125rem;
    }

    .logo-text {
        background: var(--accent-gradient);
        -webkit-background-clip: text;
        -webkit-text-fill-color: transparent;
        background-clip: text;
    }

    /* ============================================
           HERO SECTION - Email Display
           ============================================ */
    .hero {
        text-align: center;
        margin-bottom: var(--spacing-2xl);
    }

    .hero-title {
        font-size: 1.125rem;
        font-weight: 500;
        color: var(--text-secondary);
        margin-bottom: var(--spacing-lg);
    }

    /* Email Display Box */
    .email-display {
        display: flex;
        flex-direction: column;
        gap: var(--spacing-md);
        margin-bottom: var(--spacing-xl);
    }

    @media (min-width: 640px) {
        .email-display {
            flex-direction: row;
            align-items: stretch;
            justify-content: center;
        }
    }

    .email-box {
        background: var(--bg-card);
        border: 2px solid var(--border-color);
        border-radius: var(--border-radius-lg);
        padding: var(--spacing-md) var(--spacing-lg);
        display: flex;
        align-items: center;
        justify-content: center;
        min-height: 64px;
        flex: 1;
        max-width: 480px;
    }

    .email-address {
        font-family: var(--font-mono);
        font-size: 1rem;
        font-weight: 500;
        color: var(--text-primary);
        letter-spacing: 0.02em;
        word-break: break-all;
    }

    @media (min-width: 640px) {
        .email-address {
            font-size: 1.125rem;
        }
    }

    /* Copy Button */
    .btn-copy {
        display: flex;
        align-items: center;
        justify-content: center;
        gap: var(--spacing-sm);
        background: var(--accent-gradient);
        color: white;
        border: none;
        border-radius: var(--border-radius-lg);
        padding: var(--spacing-md) var(--spacing-xl);
        font-family: var(--font-primary);
        font-size: 1rem;
        font-weight: 600;
        cursor: pointer;
        transition: all var(--transition-normal);
        min-height: 64px;
        touch-action: manipulation;
    }

    .btn-copy:hover {
        transform: translateY(-2px);
        box-shadow: 0 8px 24px rgba(99, 102, 241, 0.35);
    }

    .btn-copy:active {
        transform: translateY(0);
    }

    .btn-copy svg {
        width: 20px;
        height: 20px;
        flex-shrink: 0;
    }

    /* ============================================
           TIMER DISPLAY
           ============================================ */
    .timer-section {
        margin-bottom: var(--spacing-xl);
    }

    .timer-display {
        font-family: var(--font-mono);
        font-size: 5rem;
        font-weight: 700;
        background: var(--accent-gradient);
        -webkit-background-clip: text;
        -webkit-text-fill-color: transparent;
        background-clip: text;
        line-height: 1;
        letter-spacing: 0.05em;
        text-shadow: 0 0 60px rgba(99, 102, 241, 0.3);
    }

    @media (min-width: 640px) {
        .timer-display {
            font-size: 7rem;
        }
    }

    .timer-label {
        font-size: 0.875rem;
        color: var(--text-muted);
        margin-top: var(--spacing-sm);
        text-transform: uppercase;
        letter-spacing: 0.1em;
    }

    /* ============================================
           ACTION BAR
           ============================================ */
    .action-bar {
        display: flex;
        flex-wrap: wrap;
        gap: var(--spacing-sm);
        justify-content: center;
        margin-bottom: var(--spacing-2xl);
    }

    .btn-action {
        display: flex;
        align-items: center;
        gap: var(--spacing-xs);
        background: var(--bg-tertiary);
        color: var(--text-primary);
        border: 1px solid var(--border-color);
        border-radius: var(--border-radius-md);
        padding: var(--spacing-sm) var(--spacing-md);
        font-family: var(--font-primary);
        font-size: 0.875rem;
        font-weight: 500;
        cursor: pointer;
        transition: all var(--transition-fast);
        min-height: 44px;
        touch-action: manipulation;
    }

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

    .btn-action svg {
        width: 16px;
        height: 16px;
        color: var(--text-secondary);
    }

    /* ============================================
           INBOX SECTION
           ============================================ */
    .inbox-section {
        background: var(--bg-secondary);
        border: 1px solid var(--border-color);
        border-radius: var(--border-radius-xl);
        overflow: hidden;
    }

    .inbox-header {
        display: flex;
        align-items: center;
        justify-content: space-between;
        padding: var(--spacing-lg) var(--spacing-xl);
        border-bottom: 1px solid var(--border-color);
        background: var(--bg-tertiary);
    }

    .inbox-title {
        font-size: 1.125rem;
        font-weight: 600;
        color: var(--text-primary);
    }

    .inbox-badge {
        background: var(--accent-primary);
        color: white;
        font-size: 0.75rem;
        font-weight: 600;
        padding: 0.25rem 0.625rem;
        border-radius: 9999px;
    }

    .inbox-content {
        min-height: 300px;
    }

    /* ============================================
           STATE A: EMPTY INBOX
           ============================================ */
    .empty-state {
        display: flex;
        flex-direction: column;
        align-items: center;
        justify-content: center;
        padding: var(--spacing-2xl);
        min-height: 300px;
        text-align: center;
    }

    /* CSS-Only Loading Animation */
    .loading-spinner {
        width: 48px;
        height: 48px;
        border: 3px solid var(--border-color);
        border-top-color: var(--accent-primary);
        border-radius: 50%;
        animation: spin 1s linear infinite;
        margin-bottom: var(--spacing-lg);
    }

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

    /* Alternative Pulsing Animation */
    .pulse-container {
        display: flex;
        gap: var(--spacing-sm);
        margin-bottom: var(--spacing-lg);
    }

    .pulse-dot {
        width: 12px;
        height: 12px;
        background: var(--accent-primary);
        border-radius: 50%;
        animation: pulse 1.4s ease-in-out infinite;
    }

    .pulse-dot:nth-child(1) {
        animation-delay: 0s;
    }

    .pulse-dot:nth-child(2) {
        animation-delay: 0.2s;
    }

    .pulse-dot:nth-child(3) {
        animation-delay: 0.4s;
    }

    @keyframes pulse {

        0%,
        80%,
        100% {
            transform: scale(0.6);
            opacity: 0.5;
        }

        40% {
            transform: scale(1);
            opacity: 1;
        }
    }

    .empty-text {
        font-size: 1rem;
        color: var(--text-secondary);
    }

    .empty-subtext {
        font-size: 0.875rem;
        color: var(--text-muted);
        margin-top: var(--spacing-xs);
    }

    /* ============================================
           STATE B: POPULATED INBOX
           ============================================ */
    .email-list {
        list-style: none;
    }

    .email-item {
        display: flex;
        align-items: center;
        gap: var(--spacing-md);
        padding: var(--spacing-lg) var(--spacing-xl);
        border-bottom: 1px solid var(--border-color);
        transition: background var(--transition-fast);
        cursor: pointer;
        touch-action: manipulation;
        -webkit-tap-highlight-color: transparent;
    }

    .email-item:last-child {
        border-bottom: none;
    }

    .email-item:hover {
        background: var(--bg-hover);
    }

    .email-avatar {
        width: 44px;
        height: 44px;
        border-radius: 50%;
        background: var(--accent-gradient);
        display: flex;
        align-items: center;
        justify-content: center;
        font-size: 1rem;
        font-weight: 600;
        color: white;
        flex-shrink: 0;
    }

    .email-avatar.gmail {
        background: linear-gradient(135deg, #ea4335 0%, #fbbc05 100%);
    }

    .email-avatar.outlook {
        background: linear-gradient(135deg, #0078d4 0%, #00a4ef 100%);
    }

    .email-avatar.yahoo {
        background: linear-gradient(135deg, #6001d2 0%, #7c3aed 100%);
    }

    .email-content {
        flex: 1;
        min-width: 0;
    }

    .email-sender {
        font-size: 0.875rem;
        font-weight: 600;
        color: var(--text-primary);
        margin-bottom: 0.25rem;
    }

    .email-subject {
        font-size: 0.875rem;
        color: var(--text-secondary);
        white-space: nowrap;
        overflow: hidden;
        text-overflow: ellipsis;
    }

    .email-meta {
        display: flex;
        flex-direction: column;
        align-items: flex-end;
        gap: 0.25rem;
        flex-shrink: 0;
    }

    .email-time {
        font-size: 0.75rem;
        color: var(--text-muted);
    }

    .email-unread {
        width: 8px;
        height: 8px;
        background: var(--accent-primary);
        border-radius: 50%;
    }

    /* ============================================
           FOOTER
           ============================================ */
    .footer {
        text-align: center;
        padding: var(--spacing-xl) 0;
        margin-top: var(--spacing-2xl);
    }

    .footer-text {
        font-size: 0.75rem;
        color: var(--text-muted);
    }

    /* ============================================
           UTILITY CLASSES
           ============================================ */
    .hidden {
        display: none !important;
    }