* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

:root {
    --bg-primary: #0b0b0b;
    --bg-secondary: #111111;
    --bg-tertiary: #1a1a1a;
    --bg-hover: #252525;
    --bg-card: #161616;
    --text-primary: #ffffff;
    --text-secondary: #a0a0a0;
    --text-muted: #666666;
    --accent: #00d4ff;
    --accent-glow: rgba(0, 212, 255, 0.2);
    --accent-secondary: #00ff88;
    --border: #2a2a2a;
    --danger: #ff4444;
    --success: #00ff88;
    --radius-sm: 8px;
    --radius-md: 12px;
    --radius-lg: 16px;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    background: var(--bg-primary);
    color: var(--text-primary);
    line-height: 1.6;
    min-height: 100vh;
}

/* Landing Page */
.landing {
    min-height: 100vh;
    position: relative;
    overflow: hidden;
}

.landing-bg {
    position: absolute;
    inset: 0;
    background: 
        radial-gradient(ellipse at 20% 20%, rgba(0, 212, 255, 0.08) 0%, transparent 50%),
        radial-gradient(ellipse at 80% 80%, rgba(0, 255, 136, 0.05) 0%, transparent 50%);
    pointer-events: none;
}

.landing-nav {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 24px 48px;
    position: relative;
    z-index: 10;
}

.logo {
    font-size: 24px;
    font-weight: 700;
    background: linear-gradient(135deg, var(--accent), var(--accent-secondary));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

.nav-links {
    display: flex;
    gap: 16px;
}

.landing-hero {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    min-height: calc(100vh - 100px);
    text-align: center;
    padding: 48px;
    position: relative;
    z-index: 5;
}

.landing-hero h1 {
    font-size: clamp(36px, 8vw, 72px);
    font-weight: 700;
    line-height: 1.1;
    margin-bottom: 24px;
}

.gradient {
    background: linear-gradient(135deg, var(--accent), var(--accent-secondary));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

.landing-hero p {
    font-size: 18px;
    color: var(--text-secondary);
    max-width: 500px;
    margin-bottom: 40px;
}

.landing-cta {
    display: flex;
    gap: 16px;
    margin-bottom: 60px;
}

.landing-features {
    display: flex;
    gap: 40px;
    flex-wrap: wrap;
    justify-content: center;
}

.feature {
    display: flex;
    align-items: center;
    gap: 12px;
    color: var(--text-secondary);
    font-size: 14px;
}

.feature svg {
    color: var(--accent);
}

/* Fade animations */
.fade-in {
    opacity: 0;
    transform: translateY(20px);
    animation: fadeIn 0.8s ease forwards;
}

.delay-1 { animation-delay: 0.2s; }
.delay-2 { animation-delay: 0.4s; }
.delay-3 { animation-delay: 0.6s; }

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

/* Buttons */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    padding: 12px 24px;
    border-radius: var(--radius-md);
    font-size: 14px;
    font-weight: 500;
    text-decoration: none;
    cursor: pointer;
    border: none;
    transition: all 0.2s ease;
}

.btn-primary {
    background: linear-gradient(135deg, var(--accent), #0099cc);
    color: var(--bg-primary);
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 24px var(--accent-glow);
}

.btn-ghost {
    background: transparent;
    color: var(--text-primary);
    border: 1px solid var(--border);
}

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

.btn-large {
    padding: 16px 32px;
    font-size: 16px;
}

.btn-full {
    width: 100%;
}

.btn-small {
    padding: 6px 12px;
    font-size: 12px;
}

.btn-success {
    background: var(--success);
    color: var(--bg-primary);
}

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

/* Auth Pages */
.auth-page {
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 24px;
    background: var(--bg-primary);
}

.auth-page::before {
    content: '';
    position: absolute;
    inset: 0;
    background: radial-gradient(ellipse at 50% 0%, rgba(0, 212, 255, 0.05) 0%, transparent 50%);
    pointer-events: none;
}

.auth-box {
    width: 100%;
    max-width: 400px;
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
    padding: 40px;
    position: relative;
}

.auth-logo {
    font-size: 28px;
    font-weight: 700;
    text-align: center;
    margin-bottom: 8px;
    background: linear-gradient(135deg, var(--accent), var(--accent-secondary));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

.auth-box h2 {
    text-align: center;
    margin-bottom: 24px;
    color: var(--text-secondary);
    font-size: 16px;
    font-weight: 400;
}

.auth-error {
    background: rgba(255, 68, 68, 0.1);
    border: 1px solid var(--danger);
    color: var(--danger);
    padding: 12px;
    border-radius: var(--radius-sm);
    margin-bottom: 20px;
    font-size: 14px;
}

.auth-form {
    display: flex;
    flex-direction: column;
    gap: 16px;
}

.form-group {
    display: flex;
    flex-direction: column;
    gap: 6px;
}

.form-group label {
    font-size: 13px;
    color: var(--text-secondary);
    font-weight: 500;
}

.form-group input {
    padding: 12px 16px;
    background: var(--bg-tertiary);
    border: 1px solid var(--border);
    border-radius: var(--radius-sm);
    color: var(--text-primary);
    font-size: 14px;
    transition: all 0.2s ease;
}

.form-group input:focus {
    outline: none;
    border-color: var(--accent);
    box-shadow: 0 0 0 3px var(--accent-glow);
}

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

.auth-link {
    text-align: center;
    margin-top: 20px;
    font-size: 14px;
    color: var(--text-secondary);
}

.auth-link a {
    color: var(--accent);
    text-decoration: none;
}

.auth-link a:hover {
    text-decoration: underline;
}

/* App Layout */
.app {
    display: flex;
    height: 100vh;
    overflow: hidden;
}

.sidebar {
    width: 280px;
    background: var(--bg-secondary);
    border-right: 1px solid var(--border);
    display: flex;
    flex-direction: column;
    flex-shrink: 0;
}

.sidebar-header {
    padding: 16px;
    border-bottom: 1px solid var(--border);
}

.new-chat-btn {
    display: flex;
    align-items: center;
    gap: 10px;
    padding: 12px 16px;
    background: var(--bg-tertiary);
    border: 1px solid var(--border);
    border-radius: var(--radius-md);
    color: var(--text-primary);
    text-decoration: none;
    font-size: 14px;
    font-weight: 500;
    transition: all 0.2s ease;
}

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

.sidebar-user {
    padding: 16px;
    border-bottom: 1px solid var(--border);
}

.user-info {
    display: flex;
    align-items: center;
    gap: 8px;
    margin-bottom: 4px;
}

.username {
    font-weight: 500;
    font-size: 14px;
}

.badge-premium {
    background: linear-gradient(135deg, var(--accent), var(--accent-secondary));
    color: var(--bg-primary);
    font-size: 10px;
    font-weight: 700;
    padding: 2px 8px;
    border-radius: 20px;
    text-transform: uppercase;
}

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

.chat-list {
    flex: 1;
    overflow-y: auto;
    padding: 8px;
}

.chat-item {
    display: flex;
    align-items: center;
    gap: 8px;
    padding: 4px;
    border-radius: var(--radius-sm);
    transition: background 0.2s ease;
}

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

.chat-item.active {
    background: var(--bg-tertiary);
}

.chat-link {
    flex: 1;
    display: flex;
    align-items: center;
    gap: 10px;
    padding: 10px 12px;
    color: var(--text-secondary);
    text-decoration: none;
    font-size: 13px;
    overflow: hidden;
}

.chat-link span {
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}

.chat-item.active .chat-link {
    color: var(--text-primary);
}

.delete-chat {
    background: none;
    border: none;
    color: var(--text-muted);
    cursor: pointer;
    padding: 8px;
    border-radius: var(--radius-sm);
    opacity: 0;
    transition: all 0.2s ease;
}

.chat-item:hover .delete-chat {
    opacity: 1;
}

.delete-chat:hover {
    color: var(--danger);
    background: rgba(255, 68, 68, 0.1);
}

.sidebar-footer {
    padding: 16px;
    border-top: 1px solid var(--border);
}

.logout-btn {
    display: flex;
    align-items: center;
    gap: 10px;
    color: var(--text-secondary);
    text-decoration: none;
    font-size: 14px;
    padding: 10px 12px;
    border-radius: var(--radius-sm);
    transition: all 0.2s ease;
}

.logout-btn:hover {
    background: var(--bg-hover);
    color: var(--text-primary);
}

.main {
    flex: 1;
    display: flex;
    flex-direction: column;
    min-width: 0;
}

.header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 12px 20px;
    border-bottom: 1px solid var(--border);
    background: var(--bg-primary);
}

.menu-toggle {
    display: none;
    background: none;
    border: none;
    color: var(--text-secondary);
    cursor: pointer;
    padding: 8px;
    border-radius: var(--radius-sm);
}

.menu-toggle:hover {
    background: var(--bg-hover);
    color: var(--text-primary);
}

.header-title {
    font-size: 14px;
    font-weight: 500;
    color: var(--text-secondary);
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
    max-width: 300px;
}

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

.model-select {
    padding: 8px 12px;
    background: var(--bg-tertiary);
    border: 1px solid var(--border);
    border-radius: var(--radius-sm);
    color: var(--text-primary);
    font-size: 13px;
    cursor: pointer;
    outline: none;
}

.model-select:focus {
    border-color: var(--accent);
}

.share-btn {
    background: none;
    border: none;
    color: var(--text-secondary);
    cursor: pointer;
    padding: 8px;
    border-radius: var(--radius-sm);
    transition: all 0.2s ease;
}

.share-btn:hover {
    background: var(--bg-hover);
    color: var(--accent);
}

.chat-container {
    flex: 1;
    overflow-y: auto;
    padding: 20px;
}

.welcome {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    height: 100%;
    text-align: center;
    padding: 40px;
}

.welcome h1 {
    font-size: 32px;
    font-weight: 600;
    margin-bottom: 12px;
    background: linear-gradient(135deg, var(--text-primary), var(--accent));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

.welcome-sub {
    color: var(--text-secondary);
    font-size: 16px;
}

.message {
    display: flex;
    gap: 16px;
    max-width: 900px;
    margin: 0 auto 24px;
    animation: messageIn 0.3s ease;
}

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

.message.user {
    flex-direction: row-reverse;
}

.message-avatar {
    width: 32px;
    height: 32px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    flex-shrink: 0;
}

.message.user .message-avatar {
    background: var(--accent);
    color: var(--bg-primary);
}

.message.assistant .message-avatar {
    background: var(--bg-tertiary);
    color: var(--accent);
    border: 1px solid var(--border);
}

.message-content {
    max-width: calc(100% - 60px);
    padding: 14px 18px;
    border-radius: var(--radius-md);
}

.message.user .message-content {
    background: linear-gradient(135deg, rgba(0, 212, 255, 0.1), rgba(0, 255, 136, 0.05));
    border: 1px solid rgba(0, 212, 255, 0.2);
}

.message.assistant .message-content {
    background: var(--bg-tertiary);
    border: 1px solid var(--border);
}

.message-text {
    font-size: 15px;
    line-height: 1.7;
    word-wrap: break-word;
}

.message-text pre {
    background: var(--bg-primary);
    padding: 16px;
    border-radius: var(--radius-sm);
    overflow-x: auto;
    margin: 12px 0;
    border: 1px solid var(--border);
}

.message-text code {
    font-family: 'SF Mono', Monaco, monospace;
    font-size: 13px;
}

.message-text pre code {
    background: none;
    padding: 0;
}

.message-text :not(pre) > code {
    background: var(--bg-hover);
    padding: 2px 6px;
    border-radius: 4px;
    color: var(--accent);
}

.message-actions {
    display: flex;
    gap: 8px;
    margin-top: 10px;
    opacity: 0;
    transition: opacity 0.2s ease;
}

.message:hover .message-actions {
    opacity: 1;
}

.action-btn {
    display: flex;
    align-items: center;
    gap: 6px;
    padding: 6px 10px;
    background: var(--bg-hover);
    border: 1px solid var(--border);
    border-radius: var(--radius-sm);
    color: var(--text-secondary);
    font-size: 12px;
    cursor: pointer;
    transition: all 0.2s ease;
}

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

.typing-indicator {
    margin-bottom: 24px;
}

.typing-indicator.hidden {
    display: none;
}

.typing-indicator .message-content {
    display: flex;
    align-items: center;
    gap: 6px;
    padding: 18px;
    min-width: 80px;
}

.dot {
    width: 8px;
    height: 8px;
    background: var(--accent);
    border-radius: 50%;
    animation: bounce 1.4s infinite ease-in-out;
}

.dot:nth-child(1) { animation-delay: -0.32s; }
.dot:nth-child(2) { animation-delay: -0.16s; }

@keyframes bounce {
    0%, 80%, 100% { transform: scale(0.6); opacity: 0.5; }
    40% { transform: scale(1); opacity: 1; }
}

.input-area {
    padding: 20px;
    border-top: 1px solid var(--border);
    background: var(--bg-primary);
}

.input-form {
    max-width: 800px;
    margin: 0 auto;
}

.input-wrapper {
    display: flex;
    align-items: flex-end;
    gap: 12px;
    background: var(--bg-secondary);
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
    padding: 12px 16px;
    transition: all 0.2s ease;
}

.input-wrapper:focus-within {
    border-color: var(--accent);
    box-shadow: 0 0 0 3px var(--accent-glow);
}

#messageInput {
    flex: 1;
    background: none;
    border: none;
    color: var(--text-primary);
    font-size: 15px;
    resize: none;
    max-height: 200px;
    min-height: 24px;
    outline: none;
    font-family: inherit;
}

#messageInput::placeholder {
    color: var(--text-muted);
}

#messageInput:disabled {
    color: var(--text-muted);
    cursor: not-allowed;
}

.send-btn {
    width: 36px;
    height: 36px;
    background: var(--accent);
    border: none;
    border-radius: var(--radius-sm);
    color: var(--bg-primary);
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all 0.2s ease;
    flex-shrink: 0;
}

.send-btn:hover {
    background: #33ddff;
    transform: scale(1.05);
}

.send-btn:disabled {
    background: var(--bg-tertiary);
    color: var(--text-muted);
    cursor: not-allowed;
    transform: none;
}

.input-footer {
    text-align: center;
    margin-top: 10px;
    font-size: 12px;
    color: var(--text-muted);
}

.toast {
    position: fixed;
    bottom: 100px;
    left: 50%;
    transform: translateX(-50%) translateY(100px);
    background: var(--bg-secondary);
    color: var(--text-primary);
    padding: 12px 24px;
    border-radius: var(--radius-md);
    border: 1px solid var(--accent);
    font-size: 14px;
    opacity: 0;
    transition: all 0.3s ease;
    z-index: 1000;
}

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

/* Admin */
.admin-auth .auth-logo {
    font-size: 22px;
}

.admin-page {
    min-height: 100vh;
    background: var(--bg-primary);
}

.admin-nav {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 16px 32px;
    border-bottom: 1px solid var(--border);
}

.admin-logo {
    font-size: 20px;
    font-weight: 700;
    background: linear-gradient(135deg, var(--accent), var(--accent-secondary));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

.admin-main {
    padding: 32px;
    max-width: 1200px;
    margin: 0 auto;
}

.admin-main h1 {
    font-size: 28px;
    margin-bottom: 24px;
}

.admin-main h2 {
    font-size: 20px;
    margin: 32px 0 16px;
    color: var(--text-secondary);
}

.stats-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 20px;
    margin-bottom: 32px;
}

.stat-card {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius-md);
    padding: 24px;
    text-align: center;
}

.stat-value {
    font-size: 36px;
    font-weight: 700;
    color: var(--accent);
    margin-bottom: 4px;
}

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

.users-table-wrap {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius-md);
    overflow: hidden;
}

.users-table {
    width: 100%;
    border-collapse: collapse;
}

.users-table th,
.users-table td {
    padding: 14px 16px;
    text-align: left;
    font-size: 14px;
}

.users-table th {
    background: var(--bg-tertiary);
    color: var(--text-secondary);
    font-weight: 500;
}

.users-table td {
    border-top: 1px solid var(--border);
}

.users-table tr:hover td {
    background: var(--bg-hover);
}

.badge-free {
    background: var(--bg-tertiary);
    color: var(--text-secondary);
    font-size: 11px;
    padding: 4px 10px;
    border-radius: 20px;
}

/* Mobile */
@media (max-width: 768px) {
    .landing-nav {
        padding: 16px 24px;
    }
    
    .landing-hero {
        padding: 24px;
    }
    
    .landing-cta {
        flex-direction: column;
        width: 100%;
    }
    
    .landing-cta .btn {
        width: 100%;
    }
    
    .sidebar {
        position: fixed;
        left: 0;
        top: 0;
        height: 100%;
        z-index: 100;
        transform: translateX(-100%);
        transition: transform 0.3s ease;
    }
    
    .sidebar.open {
        transform: translateX(0);
    }
    
    .menu-toggle {
        display: block;
    }
    
    .header-title {
        max-width: 150px;
    }
    
    .model-select {
        max-width: 120px;
    }
    
    .message {
        gap: 10px;
    }
    
    .message-content {
        max-width: calc(100% - 50px);
        padding: 12px 14px;
    }
    
    .message-actions {
        opacity: 1;
    }
    
    .admin-nav {
        padding: 16px;
    }
    
    .admin-main {
        padding: 16px;
    }
    
    .stats-grid {
        grid-template-columns: repeat(2, 1fr);
    }
    
    .users-table-wrap {
        overflow-x: auto;
    }
    
    .users-table {
        min-width: 600px;
    }
}

/* Scrollbar */
::-webkit-scrollbar {
    width: 8px;
    height: 8px;
}

::-webkit-scrollbar-track {
    background: var(--bg-primary);
}

::-webkit-scrollbar-thumb {
    background: var(--bg-tertiary);
    border-radius: 4px;
}

::-webkit-scrollbar-thumb:hover {
    background: var(--text-muted);
}