/* =====================================================
   FlowBridge v2.0 — Premium Design System
   Modern dark/light mode, glassmorphism, animations
   ===================================================== */

/* ===== CSS Custom Properties ===== */
:root {
    --primary: #6C63FF;
    --primary-dark: #5A52D5;
    --primary-light: #8B83FF;
    --secondary: #FF6584;
    --accent: #00D2FF;
    --success: #00C853;
    --warning: #FFB300;
    --danger: #FF5252;

    --bg-primary: #0F0F1A;
    --bg-secondary: #1A1A2E;
    --bg-card: #16213E;
    --bg-card-hover: #1C2A4A;
    --bg-input: #0A0A15;
    --bg-glass: rgba(22, 33, 62, 0.85);

    --text-primary: #EAEAEA;
    --text-secondary: #A0A0B8;
    --text-muted: #6B6B80;
    --text-link: #6C63FF;

    --border: rgba(108, 99, 255, 0.15);
    --border-focus: rgba(108, 99, 255, 0.5);
    --shadow: 0 8px 32px rgba(0, 0, 0, 0.3);
    --shadow-hover: 0 12px 40px rgba(108, 99, 255, 0.15);
    --glass-blur: blur(20px);

    --radius-sm: 8px;
    --radius-md: 12px;
    --radius-lg: 16px;
    --radius-xl: 24px;
    --radius-full: 50%;

    --font-main: 'Inter', 'Segoe UI', system-ui, -apple-system, sans-serif;
    --font-mono: 'JetBrains Mono', 'Fira Code', monospace;

    --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    --transition-fast: all 0.15s ease;
}

/* Light mode */
[data-theme="light"] {
    --bg-primary: #F5F7FA;
    --bg-secondary: #FFFFFF;
    --bg-card: #FFFFFF;
    --bg-card-hover: #F0F2F8;
    --bg-input: #F5F7FA;
    --bg-glass: rgba(255, 255, 255, 0.85);
    --text-primary: #1A1A2E;
    --text-secondary: #555570;
    --text-muted: #9999AA;
    --border: rgba(0, 0, 0, 0.08);
    --border-focus: rgba(108, 99, 255, 0.4);
    --shadow: 0 4px 24px rgba(0, 0, 0, 0.06);
    --shadow-hover: 0 8px 32px rgba(108, 99, 255, 0.1);
}

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

html {
    font-size: 16px;
    scroll-behavior: smooth;
}

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

a { color: var(--text-link); text-decoration: none; transition: var(--transition-fast); }
a:hover { color: var(--primary-light); }

::selection {
    background: var(--primary);
    color: white;
}

/* ===== Scrollbar ===== */
::-webkit-scrollbar { width: 8px; }
::-webkit-scrollbar-track { background: var(--bg-primary); }
::-webkit-scrollbar-thumb { background: var(--primary); border-radius: 4px; }
::-webkit-scrollbar-thumb:hover { background: var(--primary-light); }

/* ===== Navbar ===== */
.navbar {
    background: var(--bg-glass);
    backdrop-filter: var(--glass-blur);
    -webkit-backdrop-filter: var(--glass-blur);
    border-bottom: 1px solid var(--border);
    padding: 0.75rem 1rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
    position: sticky;
    top: 0;
    z-index: 100;
    flex-wrap: wrap;
    gap: 0.5rem;
}

@media (min-width: 768px) {
    .navbar {
        padding: 0.75rem 2rem;
        flex-wrap: nowrap;
    }
}

.nav-brand {
    font-size: 1.4rem;
    font-weight: 700;
    background: linear-gradient(135deg, var(--primary), var(--accent));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    letter-spacing: -0.02em;
    display: flex;
    align-items: center;
}

.nav-brand img {
    width: 24px;
    height: 24px;
    margin-right: 8px;
    filter: drop-shadow(0 2px 4px rgba(108, 99, 255, 0.3));
}

@media (min-width: 768px) {
    .nav-brand img {
        width: 28px;
        height: 28px;
    }
}

.nav-actions {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    flex-wrap: wrap;
}

@media (min-width: 768px) {
    .nav-actions {
        gap: 1rem;
        flex-wrap: nowrap;
    }
}

.nav-user {
    color: var(--text-secondary);
    font-weight: 500;
    font-size: 0.9rem;
}

/* ===== Buttons ===== */
.btn {
    padding: 0.6rem 1.2rem;
    border: none;
    border-radius: var(--radius-md);
    font-size: 0.85rem;
    font-weight: 600;
    cursor: pointer;
    transition: var(--transition);
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    font-family: var(--font-main);
    letter-spacing: 0.01em;
}

@media (min-width: 640px) {
    .btn {
        padding: 0.65rem 1.4rem;
        font-size: 0.9rem;
    }
}

.btn:hover { transform: translateY(-2px); }
.btn:active { transform: translateY(0); }

.btn-primary {
    background: linear-gradient(135deg, var(--primary), var(--primary-dark));
    color: white;
    box-shadow: 0 4px 15px rgba(108, 99, 255, 0.3);
}
.btn-primary:hover { box-shadow: 0 6px 20px rgba(108, 99, 255, 0.4); }

.btn-secondary {
    background: var(--bg-card);
    color: var(--text-primary);
    border: 1px solid var(--border);
}
.btn-secondary:hover { border-color: var(--primary); }

.btn-success {
    background: linear-gradient(135deg, var(--success), #00A843);
    color: white;
    box-shadow: 0 4px 15px rgba(0, 200, 83, 0.3);
}

.btn-danger {
    background: linear-gradient(135deg, var(--danger), #D32F2F);
    color: white;
}

.btn-ghost {
    background: transparent;
    color: var(--text-secondary);
    padding: 0.5rem 0.75rem;
}
.btn-ghost:hover { background: var(--bg-card); color: var(--text-primary); }

.btn-sm { padding: 0.4rem 0.8rem; font-size: 0.8rem; }
.btn-lg { 
    padding: 0.75rem 1.75rem; 
    font-size: 0.95rem; 
}

@media (min-width: 640px) {
    .btn-lg { 
        padding: 0.85rem 2rem; 
        font-size: 1rem; 
    }
}
.btn-icon { padding: 0.5rem; border-radius: var(--radius-sm); width: 36px; height: 36px; justify-content: center; }

/* ===== Cards ===== */
.card {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
    padding: 1.75rem;
    transition: var(--transition);
}

.card:hover {
    border-color: var(--primary);
    box-shadow: var(--shadow-hover);
}

.card-glass {
    background: var(--bg-glass);
    backdrop-filter: var(--glass-blur);
    -webkit-backdrop-filter: var(--glass-blur);
}

/* ===== Form Elements ===== */
.form-group { 
    margin-bottom: 1rem;
}

@media (min-width: 640px) {
    .form-group { 
        margin-bottom: 1.25rem;
    }
}
.form-label {
    display: block;
    margin-bottom: 0.5rem;
    color: var(--text-secondary);
    font-weight: 500;
    font-size: 0.9rem;
}

.form-input, .form-select {
    width: 100%;
    padding: 0.65rem 0.85rem;
    background: var(--bg-input);
    border: 1.5px solid var(--border);
    border-radius: var(--radius-md);
    color: var(--text-primary);
    font-size: 0.9rem;
    font-family: var(--font-main);
    transition: var(--transition);
    outline: none;
}

@media (min-width: 640px) {
    .form-input, .form-select {
        padding: 0.75rem 1rem;
        font-size: 0.95rem;
    }
}

.form-input:focus, .form-select:focus {
    border-color: var(--primary);
    box-shadow: 0 0 0 3px rgba(108, 99, 255, 0.15);
}

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

/* ===== Auth Pages ===== */
.auth-container {
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 1rem;
    background: var(--bg-primary);
    position: relative;
    overflow: hidden;
}

@media (min-width: 640px) {
    .auth-container {
        padding: 1.5rem;
    }
}

@media (min-width: 768px) {
    .auth-container {
        padding: 2rem;
    }
}

.auth-container::before {
    content: '';
    position: absolute;
    width: 600px;
    height: 600px;
    background: radial-gradient(circle, rgba(108, 99, 255, 0.15), transparent 70%);
    top: -200px;
    right: -200px;
    border-radius: 50%;
}

.auth-container::after {
    content: '';
    position: absolute;
    width: 400px;
    height: 400px;
    background: radial-gradient(circle, rgba(0, 210, 255, 0.1), transparent 70%);
    bottom: -100px;
    left: -100px;
    border-radius: 50%;
}

.auth-box {
    background: var(--bg-card);
    padding: 1.5rem;
    border-radius: var(--radius-lg);
    border: 1px solid var(--border);
    box-shadow: var(--shadow);
    max-width: 420px;
    width: 100%;
    position: relative;
    z-index: 1;
    animation: fadeInUp 0.5s ease;
}

@media (min-width: 640px) {
    .auth-box {
        padding: 2rem;
        border-radius: var(--radius-xl);
    }
}

@media (min-width: 768px) {
    .auth-box {
        padding: 2.5rem;
    }
}

.auth-logo {
    text-align: center;
    margin-bottom: 0.5rem;
    font-size: 2rem;
}

.auth-logo img {
    width: 50px;
    height: 50px;
    filter: drop-shadow(0 4px 8px rgba(108, 99, 255, 0.4));
    animation: float 3s ease-in-out infinite;
}

@media (min-width: 640px) {
    .auth-logo {
        font-size: 2.5rem;
    }
    
    .auth-logo img {
        width: 60px;
        height: 60px;
    }
}

@keyframes float {
    0%, 100% { transform: translateY(0px); }
    50% { transform: translateY(-10px); }
}

.auth-title {
    text-align: center;
    font-size: 1.4rem;
    font-weight: 700;
    background: linear-gradient(135deg, var(--primary), var(--accent));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    margin-bottom: 0.25rem;
}

@media (min-width: 640px) {
    .auth-title {
        font-size: 1.6rem;
    }
}

.auth-subtitle {
    text-align: center;
    color: var(--text-muted);
    margin-bottom: 1.5rem;
    font-size: 0.85rem;
}

@media (min-width: 640px) {
    .auth-subtitle {
        margin-bottom: 2rem;
        font-size: 0.95rem;
    }
}

.auth-divider {
    text-align: center;
    margin: 1.5rem 0;
    color: var(--text-muted);
    font-size: 0.9rem;
}

.auth-link {
    text-align: center;
    margin-top: 1.5rem;
    color: var(--text-secondary);
    font-size: 0.9rem;
}

.auth-link a {
    color: var(--primary);
    font-weight: 600;
}

/* ===== Dashboard ===== */
.dashboard-container {
    max-width: 1400px;
    margin: 0 auto;
    padding: 1rem;
}

@media (min-width: 640px) {
    .dashboard-container {
        padding: 1.5rem;
    }
}

@media (min-width: 1024px) {
    .dashboard-container {
        padding: 2rem;
    }
}

.welcome-banner {
    background: linear-gradient(135deg, var(--primary), #4834D4);
    border-radius: var(--radius-lg);
    padding: 1.5rem;
    margin-bottom: 1.5rem;
    color: white;
    position: relative;
    overflow: hidden;
}

@media (min-width: 640px) {
    .welcome-banner {
        border-radius: var(--radius-xl);
        padding: 2rem;
        margin-bottom: 2rem;
    }
}

@media (min-width: 1024px) {
    .welcome-banner {
        padding: 2rem 2.5rem;
    }
}

.welcome-banner::after {
    content: '';
    position: absolute;
    width: 300px;
    height: 300px;
    background: rgba(255, 255, 255, 0.08);
    border-radius: 50%;
    top: -100px;
    right: -50px;
}

.welcome-banner h1 { font-size: 1.6rem; font-weight: 700; margin-bottom: 0.5rem; position: relative; z-index: 1; }
.welcome-banner p { opacity: 0.85; position: relative; z-index: 1; }

.stats-row {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 1rem;
    margin-bottom: 1.5rem;
}

@media (min-width: 640px) {
    .stats-row {
        grid-template-columns: repeat(2, 1fr);
        gap: 1.25rem;
        margin-bottom: 2rem;
    }
}

@media (min-width: 768px) {
    .stats-row {
        grid-template-columns: repeat(4, 1fr);
    }
}

@media (min-width: 1024px) {
    .stats-row {
        grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    }
}

.stat-card {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
    padding: 1.5rem;
    text-align: center;
    transition: var(--transition);
}

.stat-card:hover { border-color: var(--primary); transform: translateY(-4px); box-shadow: var(--shadow-hover); }
.stat-icon { font-size: 2rem; margin-bottom: 0.5rem; }
.stat-value { font-size: 1.8rem; font-weight: 700; color: var(--primary); }
.stat-label { color: var(--text-muted); font-size: 0.85rem; margin-top: 0.25rem; }

.mode-cards {
    display: grid;
    grid-template-columns: 1fr;
    gap: 1rem;
}

@media (min-width: 640px) {
    .mode-cards {
        grid-template-columns: repeat(2, 1fr);
        gap: 1.25rem;
    }
}

@media (min-width: 1024px) {
    .mode-cards {
        grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
        gap: 1.5rem;
    }
}

.mode-card {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
    padding: 1.75rem 1.5rem;
    text-align: center;
    cursor: pointer;
    transition: var(--transition);
    position: relative;
    overflow: hidden;
}

@media (min-width: 640px) {
    .mode-card {
        border-radius: var(--radius-xl);
        padding: 2rem;
    }
}

@media (min-width: 1024px) {
    .mode-card {
        padding: 2.5rem 2rem;
    }
}

.mode-card:hover {
    border-color: var(--primary);
    transform: translateY(-8px);
    box-shadow: var(--shadow-hover);
}

.mode-card::before {
    content: '';
    position: absolute;
    inset: 0;
    background: linear-gradient(135deg, rgba(108, 99, 255, 0.05), transparent);
    opacity: 0;
    transition: var(--transition);
}

.mode-card:hover::before { opacity: 1; }

.mode-icon { font-size: 2.5rem; margin-bottom: 0.75rem; position: relative; z-index: 1; }

@media (min-width: 640px) {
    .mode-icon { font-size: 3rem; margin-bottom: 1rem; }
}

@media (min-width: 1024px) {
    .mode-icon { font-size: 3.5rem; }
}
.mode-title { font-size: 1.1rem; font-weight: 700; color: var(--primary); margin-bottom: 0.5rem; position: relative; z-index: 1; }

@media (min-width: 640px) {
    .mode-title { font-size: 1.15rem; margin-bottom: 0.65rem; }
}

@media (min-width: 1024px) {
    .mode-title { font-size: 1.25rem; margin-bottom: 0.75rem; }
}
.mode-desc { color: var(--text-secondary); line-height: 1.6; font-size: 0.9rem; position: relative; z-index: 1; }

/* ===== Transfer Layout ===== */
.transfer-layout {
    display: grid;
    grid-template-columns: 1fr;
    gap: 1rem;
    max-width: 1400px;
    margin: 0 auto;
    padding: 1rem;
    min-height: calc(100vh - 60px);
}

@media (min-width: 1024px) {
    .transfer-layout {
        grid-template-columns: 320px 1fr;
        gap: 1.5rem;
        padding: 1.5rem;
    }
}

/* ===== Sidebar ===== */
.sidebar {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
    padding: 1rem;
    height: fit-content;
    max-height: 400px;
    overflow-y: auto;
}

@media (min-width: 1024px) {
    .sidebar {
        padding: 1.25rem;
        position: sticky;
        top: 70px;
        max-height: calc(100vh - 90px);
    }
}

.sidebar-title {
    color: var(--text-primary);
    font-size: 1rem;
    font-weight: 700;
    margin-bottom: 1rem;
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.sidebar-search {
    margin-bottom: 1rem;
}

.sidebar-search input {
    width: 100%;
    padding: 0.6rem 0.75rem;
    background: var(--bg-input);
    border: 1px solid var(--border);
    border-radius: var(--radius-sm);
    color: var(--text-primary);
    font-size: 0.85rem;
    outline: none;
}
.sidebar-search input:focus { border-color: var(--primary); }

/* ===== File Items ===== */
.file-item {
    background: var(--bg-input);
    padding: 0.7rem;
    border-radius: var(--radius-sm);
    margin-bottom: 0.4rem;
    cursor: pointer;
    transition: var(--transition-fast);
    border: 1.5px solid transparent;
    display: flex;
    align-items: center;
    gap: 0.6rem;
}

.file-item:hover { background: var(--bg-card-hover); border-color: var(--border); }
.file-item.selected { background: var(--primary); color: white; border-color: var(--primary); }
.file-item.selected .file-size { color: rgba(255,255,255,0.7); }

.file-icon { font-size: 1.3rem; flex-shrink: 0; }
.file-info { flex: 1; min-width: 0; }
.file-name { font-weight: 500; font-size: 0.85rem; white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
.file-size { font-size: 0.75rem; color: var(--text-muted); }

.file-actions-inline {
    display: flex; gap: 0.25rem; opacity: 0; transition: var(--transition-fast);
}
.file-item:hover .file-actions-inline { opacity: 1; }

/* ===== Folder Items ===== */
.folder-item {
    background: var(--bg-input);
    padding: 0.6rem 0.7rem;
    border-radius: var(--radius-sm);
    margin-bottom: 0.4rem;
    cursor: pointer;
    display: flex;
    align-items: center;
    gap: 0.5rem;
    transition: var(--transition-fast);
    border: 1.5px solid transparent;
}
.folder-item:hover { background: var(--bg-card-hover); border-color: var(--border); }
.folder-icon { font-size: 1.2rem; }
.folder-name { font-weight: 500; font-size: 0.85rem; }

/* ===== Main Content ===== */
.main-content {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
    padding: 1.25rem;
}

@media (min-width: 640px) {
    .main-content {
        padding: 1.5rem;
    }
}

@media (min-width: 1024px) {
    .main-content {
        padding: 2rem;
    }
}

.section-title {
    font-size: 1.2rem;
    font-weight: 700;
    margin-bottom: 0.5rem;
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.section-subtitle {
    color: var(--text-muted);
    margin-bottom: 1.5rem;
    font-size: 0.9rem;
}

/* ===== Upload Area (Drag & Drop) ===== */
.upload-zone {
    border: 2px dashed var(--border);
    border-radius: var(--radius-lg);
    padding: 1.5rem;
    text-align: center;
    transition: var(--transition);
    cursor: pointer;
    background: var(--bg-input);
    margin-bottom: 1rem;
}

@media (min-width: 640px) {
    .upload-zone {
        padding: 2rem;
    }
}

@media (min-width: 1024px) {
    .upload-zone {
        padding: 2.5rem;
    }
}

.upload-zone:hover, .upload-zone.drag-over {
    border-color: var(--primary);
    background: rgba(108, 99, 255, 0.05);
}

.upload-zone-icon { font-size: 2.5rem; margin-bottom: 0.5rem; opacity: 0.7; }

@media (min-width: 640px) {
    .upload-zone-icon { font-size: 3rem; margin-bottom: 0.75rem; }
}
.upload-zone-text { color: var(--text-secondary); font-size: 0.95rem; }
.upload-zone-hint { color: var(--text-muted); font-size: 0.8rem; margin-top: 0.5rem; }

/* ===== Progress Bar ===== */
.progress-container { margin: 1rem 0; }
.progress-bar {
    width: 100%;
    height: 10px;
    background: var(--bg-input);
    border-radius: 5px;
    overflow: hidden;
}

.progress-fill {
    height: 100%;
    background: linear-gradient(90deg, var(--primary), var(--accent));
    border-radius: 5px;
    transition: width 0.3s ease;
    width: 0%;
    position: relative;
}

.progress-fill::after {
    content: '';
    position: absolute;
    inset: 0;
    background: linear-gradient(90deg, transparent, rgba(255,255,255,0.2), transparent);
    animation: shimmer 2s infinite;
}

.progress-text {
    display: flex;
    justify-content: space-between;
    margin-top: 0.5rem;
    font-size: 0.85rem;
    color: var(--text-secondary);
}

/* ===== Share Section ===== */
.share-result {
    background: var(--bg-input);
    border: 1px solid var(--border);
    border-radius: var(--radius-md);
    padding: 1.5rem;
    margin-top: 1rem;
}

.share-field {
    margin-bottom: 1rem;
}

.share-field label {
    display: block;
    font-size: 0.8rem;
    color: var(--text-muted);
    margin-bottom: 0.4rem;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    font-weight: 600;
}

.share-field .copy-row {
    display: flex;
    gap: 0.5rem;
}

.share-field input {
    flex: 1;
    padding: 0.6rem;
    background: var(--bg-primary);
    border: 1px solid var(--border);
    border-radius: var(--radius-sm);
    color: var(--text-primary);
    font-family: var(--font-mono);
    font-size: 0.85rem;
}

.otp-display {
    font-size: 2rem;
    font-weight: 700;
    letter-spacing: 0.5rem;
    color: var(--primary);
    font-family: var(--font-mono);
    text-align: center;
    padding: 0.75rem;
    background: var(--bg-primary);
    border-radius: var(--radius-md);
    border: 2px solid var(--primary);
}

.qr-container {
    text-align: center;
    padding: 1rem;
}

.qr-container img {
    max-width: 180px;
    border-radius: var(--radius-md);
    border: 3px solid white;
}

/* ===== Toast Notifications ===== */
.toast-container {
    position: fixed;
    top: 70px;
    right: 10px;
    z-index: 10000;
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
    max-width: calc(100vw - 20px);
}

@media (min-width: 640px) {
    .toast-container {
        top: 80px;
        right: 20px;
        max-width: 420px;
    }
}

.toast {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius-md);
    padding: 0.75rem 1rem;
    min-width: 280px;
    max-width: 100%;
    box-shadow: var(--shadow);
    display: flex;
    align-items: center;
    gap: 0.75rem;
    animation: slideInRight 0.3s ease, fadeOut 0.3s ease 4.7s forwards;
    backdrop-filter: var(--glass-blur);
}

@media (min-width: 640px) {
    .toast {
        padding: 0.85rem 1.25rem;
        min-width: 300px;
    }
}

.toast-success { border-left: 4px solid var(--success); }
.toast-error { border-left: 4px solid var(--danger); }
.toast-info { border-left: 4px solid var(--primary); }
.toast-warning { border-left: 4px solid var(--warning); }

.toast-icon { font-size: 1.2rem; flex-shrink: 0; }
.toast-message { font-size: 0.9rem; color: var(--text-primary); flex: 1; }
.toast-close { cursor: pointer; color: var(--text-muted); font-size: 1.1rem; padding: 0.25rem; }

/* ===== Status Messages ===== */
.alert {
    padding: 0.85rem 1.25rem;
    border-radius: var(--radius-md);
    margin: 1rem 0;
    font-size: 0.9rem;
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.alert-success { background: rgba(0, 200, 83, 0.1); color: var(--success); border: 1px solid rgba(0, 200, 83, 0.2); }
.alert-error { background: rgba(255, 82, 82, 0.1); color: var(--danger); border: 1px solid rgba(255, 82, 82, 0.2); }
.alert-info { background: rgba(108, 99, 255, 0.1); color: var(--primary-light); border: 1px solid rgba(108, 99, 255, 0.2); }
.alert-warning { background: rgba(255, 179, 0, 0.1); color: var(--warning); border: 1px solid rgba(255, 179, 0, 0.2); }

/* ===== Loading Skeleton ===== */
.skeleton {
    background: linear-gradient(90deg, var(--bg-input) 25%, var(--bg-card-hover) 50%, var(--bg-input) 75%);
    background-size: 200% 100%;
    animation: skeleton 1.5s infinite;
    border-radius: var(--radius-sm);
}

.skeleton-text { height: 14px; margin-bottom: 8px; width: 80%; }
.skeleton-title { height: 20px; margin-bottom: 12px; width: 60%; }
.skeleton-block { height: 60px; }

/* ===== Preview Modal ===== */
.modal-overlay {
    position: fixed;
    inset: 0;
    background: rgba(0, 0, 0, 0.7);
    z-index: 1000;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 1rem;
    animation: fadeIn 0.2s ease;
    backdrop-filter: blur(4px);
}

@media (min-width: 640px) {
    .modal-overlay {
        padding: 2rem;
    }
}

.modal-content {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
    max-width: 900px;
    max-height: 90vh;
    width: 100%;
    overflow: hidden;
    animation: fadeInUp 0.3s ease;
    display: flex;
    flex-direction: column;
}

@media (min-width: 640px) {
    .modal-content {
        border-radius: var(--radius-xl);
        max-height: 85vh;
    }
}

.modal-header {
    padding: 1rem 1.25rem;
    border-bottom: 1px solid var(--border);
    display: flex;
    justify-content: space-between;
    align-items: center;
}

@media (min-width: 640px) {
    .modal-header {
        padding: 1.25rem 1.5rem;
    }
}

.modal-header h3 { font-size: 1rem; font-weight: 600; }
.modal-close { cursor: pointer; font-size: 1.5rem; color: var(--text-muted); background: none; border: none; }

.modal-body {
    padding: 1rem;
    overflow-y: auto;
    flex: 1;
}

@media (min-width: 640px) {
    .modal-body {
        padding: 1.5rem;
    }
}

.modal-body img {
    max-width: 100%;
    max-height: 60vh;
    display: block;
    margin: 0 auto;
    border-radius: var(--radius-md);
}

.modal-body pre {
    background: var(--bg-input);
    padding: 1rem;
    border-radius: var(--radius-md);
    overflow-x: auto;
    font-family: var(--font-mono);
    font-size: 0.85rem;
    line-height: 1.6;
    color: var(--text-primary);
    max-height: 60vh;
}

/* ===== Theme Toggle ===== */
.theme-toggle {
    width: 36px;
    height: 36px;
    border: 1px solid var(--border);
    border-radius: var(--radius-sm);
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    background: var(--bg-input);
    font-size: 1.1rem;
    transition: var(--transition-fast);
}

.theme-toggle:hover { border-color: var(--primary); background: var(--bg-card-hover); }

/* ===== Storage Bar ===== */
.storage-bar {
    margin-top: 1rem;
}

.storage-track {
    height: 6px;
    background: var(--bg-input);
    border-radius: 3px;
    overflow: hidden;
}

.storage-fill {
    height: 100%;
    background: linear-gradient(90deg, var(--primary), var(--accent));
    border-radius: 3px;
    transition: width 0.5s ease;
}

.storage-text {
    display: flex;
    justify-content: space-between;
    font-size: 0.75rem;
    color: var(--text-muted);
    margin-top: 0.3rem;
}

/* ===== Tags ===== */
.tag {
    display: inline-flex;
    align-items: center;
    gap: 0.3rem;
    padding: 0.2rem 0.6rem;
    background: rgba(108, 99, 255, 0.15);
    color: var(--primary-light);
    border-radius: 20px;
    font-size: 0.75rem;
    font-weight: 500;
}

.tag-remove {
    cursor: pointer;
    opacity: 0.7;
}

.tag-remove:hover { opacity: 1; }

/* ===== Empty State ===== */
.empty-state {
    text-align: center;
    padding: 3rem 1rem;
    color: var(--text-muted);
}

.empty-state-icon { font-size: 3rem; margin-bottom: 0.75rem; opacity: 0.5; }
.empty-state-text { font-size: 0.95rem; }
.empty-state-hint { font-size: 0.8rem; margin-top: 0.5rem; color: var(--text-muted); }

/* ===== Error Page ===== */
.error-page {
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    text-align: center;
    padding: 2rem;
}

.error-code { font-size: 6rem; font-weight: 800; color: var(--primary); opacity: 0.3; }
.error-title { font-size: 1.5rem; font-weight: 700; margin-bottom: 0.5rem; }
.error-text { color: var(--text-secondary); margin-bottom: 2rem; }

/* ===== Animations ===== */
@keyframes fadeIn { from { opacity: 0; } to { opacity: 1; } }
@keyframes fadeOut { from { opacity: 1; } to { opacity: 0; } }
@keyframes fadeInUp { from { opacity: 0; transform: translateY(20px); } to { opacity: 1; transform: translateY(0); } }
@keyframes slideInRight { from { opacity: 0; transform: translateX(100px); } to { opacity: 1; transform: translateX(0); } }
@keyframes skeleton { 0% { background-position: 200% 0; } 100% { background-position: -200% 0; } }
@keyframes shimmer { 0% { transform: translateX(-100%); } 100% { transform: translateX(100%); } }
@keyframes pulse { 0%, 100% { opacity: 1; } 50% { opacity: 0.5; } }
@keyframes spin { to { transform: rotate(360deg); } }

.animate-fade-in { animation: fadeIn 0.3s ease; }
.animate-fade-up { animation: fadeInUp 0.4s ease; }
.animate-pulse { animation: pulse 2s infinite; }
.spinner { animation: spin 1s linear infinite; display: inline-block; }

/* ===== Responsive ===== */
@media (max-width: 1024px) {
    .transfer-layout {
        grid-template-columns: 1fr;
    }
    .sidebar {
        position: static;
        max-height: 400px;
    }
}

@media (max-width: 768px) {
    html {
        font-size: 15px;
    }
    .navbar { 
        padding: 0.6rem 1rem;
    }
    .nav-brand { 
        font-size: 1.2rem;
    }
    .nav-actions {
        gap: 0.5rem;
    }
    .btn-sm {
        padding: 0.35rem 0.6rem;
        font-size: 0.75rem;
    }
    .dashboard-container { 
        padding: 1rem;
    }
    .auth-box { 
        padding: 1.5rem;
        margin: 1rem;
    }
    .mode-cards { 
        grid-template-columns: 1fr;
    }
    .stats-row { 
        grid-template-columns: repeat(2, 1fr);
        gap: 0.75rem;
    }
    .stat-card {
        padding: 1.25rem;
    }
    .stat-icon {
        font-size: 1.75rem;
    }
    .stat-value {
        font-size: 1.5rem;
    }
    .welcome-banner { 
        padding: 1.5rem;
    }
    .welcome-banner h1 { 
        font-size: 1.3rem;
    }
    .main-content { 
        padding: 1.25rem;
    }
    .modal-content { 
        margin: 0.5rem;
        border-radius: var(--radius-lg);
    }
    .card {
        padding: 1.25rem;
    }
}

@media (max-width: 480px) {
    html {
        font-size: 14px;
    }
    .stats-row { 
        grid-template-columns: 1fr;
        gap: 0.75rem;
    }
    .nav-user { 
        display: none;
    }
    .nav-actions {
        gap: 0.4rem;
    }
    .btn {
        padding: 0.5rem 1rem;
        font-size: 0.85rem;
    }
    .btn-sm {
        padding: 0.3rem 0.5rem;
        font-size: 0.7rem;
    }
    .mode-card {
        padding: 1.5rem 1.25rem;
    }
    .mode-icon {
        font-size: 2.5rem;
    }
    .mode-title {
        font-size: 1rem;
    }
    .mode-desc {
        font-size: 0.85rem;
    }
    .welcome-banner h1 {
        font-size: 1.1rem;
    }
    .welcome-banner p {
        font-size: 0.85rem;
    }
    .stat-card {
        padding: 1rem;
    }
    .stat-icon {
        font-size: 1.5rem;
    }
    .stat-value {
        font-size: 1.3rem;
    }
    .stat-label {
        font-size: 0.75rem;
    }
}

/* ===== Progress Bars ===== */
.progress-bar-bg {
    width: 100%;
    height: 8px;
    background: var(--bg-input);
    border-radius: var(--radius-full);
    overflow: hidden;
}

.progress-bar-fill {
    height: 100%;
    background: linear-gradient(90deg, var(--primary), var(--accent));
    border-radius: var(--radius-full);
    transition: width 0.3s ease;
}

/* ===== Alert Boxes ===== */
.alert {
    padding: 0.75rem 1rem;
    border-radius: var(--radius-sm);
    font-size: 0.9rem;
    line-height: 1.5;
    border: 1px solid var(--border);
}

.alert-info {
    background: rgba(108, 99, 255, 0.1);
    border-color: rgba(108, 99, 255, 0.2);
    color: var(--primary-light);
}

.alert-success {
    background: rgba(0, 200, 83, 0.1);
    border-color: rgba(0, 200, 83, 0.2);
    color: var(--success);
}

.alert-warning {
    background: rgba(255, 179, 0, 0.1);
    border-color: rgba(255, 179, 0, 0.2);
    color: var(--warning);
}

.alert-danger {
    background: rgba(255, 82, 82, 0.1);
    border-color: rgba(255, 82, 82, 0.2);
    color: var(--danger);
}

/* ===== Spinner ===== */
.spinner {
    display: inline-block;
    animation: spin 1s linear infinite;
}

@keyframes spin {
    from { transform: rotate(0deg); }
    to { transform: rotate(360deg); }
}

/* ===== Large Button ===== */
.btn-lg {
    padding: 0.875rem 2rem;
    font-size: 1.1rem;
    font-weight: 600;
}