/* ==================== CSS RESET & VARIABLES ==================== */
:root {
    /* Colors */
    --color-primary: #6366f1;
    --color-primary-dark: #4f46e5;
    --color-primary-light: #818cf8;
    --color-secondary: #0ea5e9;
    --color-success: #10b981;
    --color-danger: #ef4444;
    --color-warning: #f59e0b;
    
    /* Neutrals */
    --color-bg: #0f0f23;
    --color-bg-secondary: #1a1a2e;
    --color-bg-tertiary: #16213e;
    --color-surface: #1e1e3f;
    --color-surface-hover: #2a2a4a;
    --color-border: #2d2d5a;
    --color-border-light: #3d3d6a;
    
    /* Text */
    --color-text: #f1f5f9;
    --color-text-secondary: #94a3b8;
    --color-text-muted: #64748b;
    
    /* Gradients */
    --gradient-primary: linear-gradient(135deg, #6366f1 0%, #8b5cf6 50%, #d946ef 100%);
    --gradient-secondary: linear-gradient(135deg, #0ea5e9 0%, #6366f1 100%);
    --gradient-surface: linear-gradient(145deg, #1e1e3f 0%, #16213e 100%);
    
    /* Shadows */
    --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.3);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.3), 0 2px 4px -1px rgba(0, 0, 0, 0.2);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.3), 0 4px 6px -2px rgba(0, 0, 0, 0.2);
    --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.4), 0 10px 10px -5px rgba(0, 0, 0, 0.2);
    --shadow-glow: 0 0 20px rgba(99, 102, 241, 0.3);
    
    /* Spacing */
    --spacing-xs: 0.25rem;
    --spacing-sm: 0.5rem;
    --spacing-md: 1rem;
    --spacing-lg: 1.5rem;
    --spacing-xl: 2rem;
    --spacing-2xl: 3rem;
    
    /* Border Radius */
    --radius-sm: 0.375rem;
    --radius-md: 0.5rem;
    --radius-lg: 0.75rem;
    --radius-xl: 1rem;
    --radius-full: 9999px;
    
    /* Transitions */
    --transition-fast: 150ms ease;
    --transition-base: 200ms ease;
    --transition-slow: 300ms ease;
    
    /* Font */
    --font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
}

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

html {
    scroll-behavior: smooth;
}

body {
    font-family: var(--font-family);
    background-color: var(--color-bg);
    color: var(--color-text);
    line-height: 1.6;
    min-height: 100vh;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

/* ==================== LAYOUT ==================== */
.app-container {
    display: flex;
    flex-direction: column;
    min-height: 100vh;
}

.container {
    width: 100%;
    max-width: 800px;
    margin: 0 auto;
    padding: 0 var(--spacing-md);
}

/* ==================== HEADER ==================== */
.header {
    position: sticky;
    top: 0;
    z-index: 100;
    background: rgba(15, 15, 35, 0.8);
    backdrop-filter: blur(20px);
    border-bottom: 1px solid var(--color-border);
}

.header-content {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: var(--spacing-md) 0;
}

.logo {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    text-decoration: none;
    color: var(--color-text);
    font-weight: 700;
    font-size: 1.25rem;
}

.logo-icon {
    width: 32px;
    height: 32px;
    color: var(--color-primary);
}

.nav {
    display: flex;
    gap: var(--spacing-lg);
}

.nav-link {
    color: var(--color-text-secondary);
    text-decoration: none;
    font-size: 0.875rem;
    font-weight: 500;
    transition: color var(--transition-fast);
}

.nav-link:hover {
    color: var(--color-text);
}

/* ==================== HERO ==================== */
.hero {
    padding: var(--spacing-2xl) 0 var(--spacing-xl);
    text-align: center;
}

.hero-title {
    font-size: clamp(2rem, 5vw, 3rem);
    font-weight: 700;
    margin-bottom: var(--spacing-md);
    line-height: 1.2;
}

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

.hero-subtitle {
    font-size: 1.125rem;
    color: var(--color-text-secondary);
    max-width: 500px;
    margin: 0 auto;
}

/* ==================== MAIN APP ==================== */
.main-app {
    flex: 1;
    padding-bottom: var(--spacing-2xl);
}

/* Email Generator Card */
.email-generator-card {
    background: var(--gradient-surface);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-xl);
    padding: var(--spacing-xl);
    margin-bottom: var(--spacing-xl);
    box-shadow: var(--shadow-lg);
}

/* Email Display */
.email-display {
    background: var(--color-bg);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-lg);
    padding: var(--spacing-xl);
    margin-bottom: var(--spacing-lg);
    min-height: 120px;
    display: flex;
    align-items: center;
    justify-content: center;
}

.email-placeholder {
    text-align: center;
    color: var(--color-text-muted);
}

.placeholder-icon {
    width: 48px;
    height: 48px;
    margin-bottom: var(--spacing-md);
    opacity: 0.5;
}

.email-active {
    width: 100%;
}

.email-address-wrapper {
    text-align: center;
}

.email-label {
    display: block;
    font-size: 0.75rem;
    text-transform: uppercase;
    letter-spacing: 0.1em;
    color: var(--color-text-muted);
    margin-bottom: var(--spacing-sm);
}

.email-address-box {
    display: inline-flex;
    align-items: center;
    gap: var(--spacing-md);
    background: var(--color-surface);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-lg);
    padding: var(--spacing-md) var(--spacing-lg);
}

.email-address {
    font-size: 1.25rem;
    font-weight: 600;
    color: var(--color-primary-light);
    word-break: break-all;
}

.email-meta {
    display: flex;
    justify-content: center;
    margin-top: var(--spacing-md);
}

.email-timer {
    display: inline-flex;
    align-items: center;
    gap: var(--spacing-xs);
    font-size: 0.875rem;
    color: var(--color-text-secondary);
}

.email-timer svg {
    width: 16px;
    height: 16px;
}

/* Options */
.email-options {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: var(--spacing-md);
    margin-bottom: var(--spacing-lg);
}

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

.option-label {
    font-size: 0.875rem;
    font-weight: 500;
    color: var(--color-text-secondary);
}

.select-input,
.text-input {
    background: var(--color-bg);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-md);
    padding: var(--spacing-sm) var(--spacing-md);
    color: var(--color-text);
    font-size: 0.875rem;
    font-family: inherit;
    transition: border-color var(--transition-fast), box-shadow var(--transition-fast);
}

.select-input:focus,
.text-input:focus {
    outline: none;
    border-color: var(--color-primary);
    box-shadow: 0 0 0 3px rgba(99, 102, 241, 0.2);
}

.checkbox-group {
    justify-content: flex-end;
    flex-direction: row;
    align-items: center;
}

.checkbox-label {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    cursor: pointer;
    font-size: 0.875rem;
    color: var(--color-text-secondary);
}

.checkbox-label input {
    display: none;
}

.checkmark {
    width: 18px;
    height: 18px;
    border: 2px solid var(--color-border);
    border-radius: var(--radius-sm);
    transition: all var(--transition-fast);
    position: relative;
}

.checkbox-label input:checked + .checkmark {
    background: var(--color-primary);
    border-color: var(--color-primary);
}

.checkbox-label input:checked + .checkmark::after {
    content: '';
    position: absolute;
    left: 5px;
    top: 2px;
    width: 4px;
    height: 8px;
    border: solid white;
    border-width: 0 2px 2px 0;
    transform: rotate(45deg);
}

/* Buttons */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: var(--spacing-sm);
    padding: var(--spacing-md) var(--spacing-xl);
    border: none;
    border-radius: var(--radius-lg);
    font-size: 0.875rem;
    font-weight: 600;
    font-family: inherit;
    cursor: pointer;
    transition: all var(--transition-base);
}

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

.btn-primary {
    background: var(--gradient-primary);
    color: white;
    box-shadow: var(--shadow-md), var(--shadow-glow);
}

.btn-primary:hover:not(:disabled) {
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg), 0 0 30px rgba(99, 102, 241, 0.4);
}

.btn-secondary {
    background: var(--color-surface);
    color: var(--color-text);
    border: 1px solid var(--color-border);
}

.btn-secondary:hover:not(:disabled) {
    background: var(--color-surface-hover);
    border-color: var(--color-border-light);
}

.btn-danger {
    background: var(--color-danger);
    color: white;
}

.btn-danger:hover:not(:disabled) {
    background: #dc2626;
}

.btn:disabled {
    opacity: 0.5;
    cursor: not-allowed;
}

.btn-icon {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 36px;
    height: 36px;
    background: transparent;
    border: 1px solid var(--color-border);
    border-radius: var(--radius-md);
    color: var(--color-text-secondary);
    cursor: pointer;
    transition: all var(--transition-fast);
}

.btn-icon:hover {
    background: var(--color-surface);
    color: var(--color-text);
    border-color: var(--color-border-light);
}

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

.action-buttons {
    display: flex;
    gap: var(--spacing-md);
    justify-content: center;
}

/* ==================== INBOX ==================== */
.inbox-section {
    background: var(--gradient-surface);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-xl);
    overflow: hidden;
    box-shadow: var(--shadow-lg);
}

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

.inbox-title {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    font-size: 1rem;
    font-weight: 600;
}

.inbox-title svg {
    width: 20px;
    height: 20px;
    color: var(--color-primary);
}

.message-count {
    font-size: 0.875rem;
    color: var(--color-text-muted);
}

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

.inbox-empty,
.inbox-loading {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    padding: var(--spacing-2xl);
    text-align: center;
    color: var(--color-text-muted);
}

.empty-icon {
    width: 64px;
    height: 64px;
    margin-bottom: var(--spacing-md);
    opacity: 0.3;
}

.inbox-empty p {
    font-weight: 500;
    margin-bottom: var(--spacing-xs);
}

.inbox-empty span {
    font-size: 0.875rem;
}

/* Spinner */
.spinner {
    width: 40px;
    height: 40px;
    border: 3px solid var(--color-border);
    border-top-color: var(--color-primary);
    border-radius: 50%;
    animation: spin 1s linear infinite;
    margin-bottom: var(--spacing-md);
}

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

/* Message List */
.message-list {
    padding: var(--spacing-sm);
}

.message-item {
    display: flex;
    align-items: flex-start;
    gap: var(--spacing-md);
    padding: var(--spacing-md);
    border-radius: var(--radius-lg);
    cursor: pointer;
    transition: background-color var(--transition-fast);
}

.message-item:hover {
    background: var(--color-surface-hover);
}

.message-item.unread {
    background: rgba(99, 102, 241, 0.1);
}

.message-item.unread:hover {
    background: rgba(99, 102, 241, 0.15);
}

.message-avatar {
    width: 40px;
    height: 40px;
    border-radius: var(--radius-full);
    background: var(--gradient-secondary);
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 600;
    font-size: 0.875rem;
    color: white;
    flex-shrink: 0;
}

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

.message-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    margin-bottom: var(--spacing-xs);
}

.message-sender {
    font-weight: 600;
    font-size: 0.875rem;
    color: var(--color-text);
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}

.message-time {
    font-size: 0.75rem;
    color: var(--color-text-muted);
    flex-shrink: 0;
    margin-left: var(--spacing-sm);
}

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

/* ==================== MODAL ==================== */
.modal-overlay {
    position: fixed;
    inset: 0;
    background: rgba(0, 0, 0, 0.7);
    backdrop-filter: blur(4px);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 1000;
    padding: var(--spacing-md);
}

.modal {
    background: var(--color-bg-secondary);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-xl);
    width: 100%;
    max-width: 600px;
    max-height: 80vh;
    display: flex;
    flex-direction: column;
    box-shadow: var(--shadow-xl);
    animation: modalIn 0.2s ease;
}

@keyframes modalIn {
    from {
        opacity: 0;
        transform: scale(0.95) translateY(10px);
    }
    to {
        opacity: 1;
        transform: scale(1) translateY(0);
    }
}

.modal-header {
    display: flex;
    align-items: flex-start;
    justify-content: space-between;
    gap: var(--spacing-md);
    padding: var(--spacing-lg);
    border-bottom: 1px solid var(--color-border);
}

.modal-title {
    font-size: 1.125rem;
    font-weight: 600;
    line-height: 1.4;
    word-break: break-word;
}

.modal-close {
    flex-shrink: 0;
}

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

.sender-info {
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
}

.sender-avatar {
    width: 40px;
    height: 40px;
    border-radius: var(--radius-full);
    background: var(--gradient-primary);
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 600;
    color: white;
}

.sender-details {
    display: flex;
    flex-direction: column;
}

.sender-name {
    font-weight: 600;
    font-size: 0.875rem;
}

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

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

.modal-body {
    flex: 1;
    overflow-y: auto;
    padding: var(--spacing-lg);
}

.modal-body iframe {
    width: 100%;
    min-height: 300px;
    border: none;
    background: white;
    border-radius: var(--radius-md);
}

.modal-footer {
    display: flex;
    justify-content: flex-end;
    padding: var(--spacing-md) var(--spacing-lg);
    border-top: 1px solid var(--color-border);
}

/* ==================== TOAST ==================== */
.toast-container {
    position: fixed;
    bottom: var(--spacing-lg);
    right: var(--spacing-lg);
    z-index: 2000;
    display: flex;
    flex-direction: column;
    gap: var(--spacing-sm);
}

.toast {
    background: var(--color-surface);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-lg);
    padding: var(--spacing-md) var(--spacing-lg);
    box-shadow: var(--shadow-lg);
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
    animation: toastIn 0.3s ease;
    max-width: 350px;
}

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

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

.toast-icon {
    width: 20px;
    height: 20px;
    flex-shrink: 0;
}

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

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

.toast-message {
    font-size: 0.875rem;
}

@keyframes toastIn {
    from {
        opacity: 0;
        transform: translateX(100%);
    }
    to {
        opacity: 1;
        transform: translateX(0);
    }
}

@keyframes toastOut {
    from {
        opacity: 1;
        transform: translateX(0);
    }
    to {
        opacity: 0;
        transform: translateX(100%);
    }
}

/* ==================== FOOTER ==================== */
.footer {
    padding: var(--spacing-xl) 0;
    text-align: center;
    border-top: 1px solid var(--color-border);
    color: var(--color-text-muted);
    font-size: 0.875rem;
}

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

/* ==================== RESPONSIVE ==================== */
@media (max-width: 640px) {
    .header-content {
        flex-direction: column;
        gap: var(--spacing-md);
    }
    
    .email-options {
        grid-template-columns: 1fr;
    }
    
    .action-buttons {
        flex-direction: column;
    }
    
    .action-buttons .btn {
        width: 100%;
    }
    
    .email-address {
        font-size: 1rem;
    }
    
    .modal-meta {
        flex-direction: column;
        align-items: flex-start;
        gap: var(--spacing-md);
    }
    
    .toast-container {
        left: var(--spacing-md);
        right: var(--spacing-md);
    }
    
    .toast {
        max-width: none;
    }
}