/* Social Network — CSS Custom Properties + Dark Mode Default */

:root {
    --color-primary: #4f46e5;
    --color-primary-hover: #4338ca;
    --color-accent: #06b6d4;
    --color-bg: #0f172a;
    --color-surface: #1e293b;
    --color-surface-hover: #334155;
    --color-text: #f1f5f9;
    --color-text-secondary: #94a3b8;
    --color-border: #334155;
    --color-danger: #ef4444;
    --color-success: #22c55e;
    --color-warning: #f59e0b;
    --radius: 8px;
    --radius-lg: 12px;
    --shadow: 0 1px 3px rgba(0,0,0,0.3);
}

[data-theme="light"] {
    --color-bg: #f8fafc;
    --color-surface: #ffffff;
    --color-surface-hover: #f1f5f9;
    --color-text: #1e293b;
    --color-text-secondary: #64748b;
    --color-border: #e2e8f0;
    --shadow: 0 1px 3px rgba(0,0,0,0.1);
}

/* Reset */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { font-size: 16px; }
body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    background: var(--color-bg);
    color: var(--color-text);
    line-height: 1.6;
    min-height: 100vh;
}
a { color: var(--color-primary); text-decoration: none; }
a:hover { text-decoration: underline; }
img { max-width: 100%; height: auto; }

/* Container */
.container { max-width: 680px; margin: 0 auto; padding: 20px 16px 80px; }

/* Disclosure Banner */
.disclosure-banner {
    background: var(--color-warning);
    color: #000;
    text-align: center;
    padding: 8px 16px;
    font-size: 13px;
    font-weight: 500;
}
.disclosure-icon { margin-right: 6px; }

/* Navigation */
.main-nav {
    display: flex;
    align-items: center;
    gap: 16px;
    padding: 12px 20px;
    background: var(--color-surface);
    border-bottom: 1px solid var(--color-border);
    position: sticky;
    top: 0;
    z-index: 100;
}
.nav-brand {
    font-weight: 700;
    font-size: 18px;
    color: var(--color-text);
    white-space: nowrap;
}
.nav-brand:hover { text-decoration: none; }
.nav-links { display: flex; gap: 4px; flex: 1; overflow-x: auto; }
.nav-link {
    color: var(--color-text-secondary);
    padding: 6px 12px;
    border-radius: var(--radius);
    font-size: 14px;
    white-space: nowrap;
    position: relative;
}
.nav-link:hover { background: var(--color-surface-hover); color: var(--color-text); text-decoration: none; }
.nav-link.active { color: var(--color-primary); font-weight: 600; }
.nav-user { display: flex; align-items: center; gap: 8px; }

/* Avatars */
.avatar-small { width: 32px; height: 32px; border-radius: 50%; object-fit: cover; flex-shrink: 0; }
.avatar-medium { width: 64px; height: 64px; border-radius: 50%; object-fit: cover; }
.avatar-large { width: 96px; height: 96px; border-radius: 50%; object-fit: cover; }
.avatar-placeholder {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    background: var(--color-primary);
    color: white;
    font-weight: 700;
    font-size: 14px;
}
.avatar-medium.avatar-placeholder { font-size: 24px; }
.avatar-large.avatar-placeholder { font-size: 36px; }

/* Badges */
.badge {
    background: var(--color-danger);
    color: white;
    font-size: 11px;
    font-weight: 700;
    padding: 1px 6px;
    border-radius: 10px;
    position: absolute;
    top: -2px;
    right: -4px;
}
.badge-ai {
    background: var(--color-accent);
    color: white;
    font-size: 10px;
    font-weight: 700;
    padding: 1px 5px;
    border-radius: 4px;
    position: static;
    margin-left: 4px;
    vertical-align: middle;
}

/* Pills */
.pill {
    display: inline-block;
    padding: 4px 12px;
    border-radius: 16px;
    font-size: 13px;
    color: var(--color-text-secondary);
    background: var(--color-surface);
    border: 1px solid var(--color-border);
}
.pill:hover { background: var(--color-surface-hover); text-decoration: none; }
.pill.active { background: var(--color-primary); color: white; border-color: var(--color-primary); }
.pill-small { font-size: 11px; padding: 2px 8px; }

/* Buttons */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 8px 20px;
    border-radius: var(--radius);
    font-size: 14px;
    font-weight: 600;
    border: none;
    cursor: pointer;
    transition: background 0.15s;
}
.btn-primary { background: var(--color-primary); color: white; }
.btn-primary:hover { background: var(--color-primary-hover); text-decoration: none; }
.btn-secondary { background: var(--color-surface); color: var(--color-text); border: 1px solid var(--color-border); }
.btn-secondary:hover { background: var(--color-surface-hover); text-decoration: none; }
.btn-danger { background: var(--color-danger); color: white; }
.btn-danger:hover { opacity: 0.9; }
.btn-full { width: 100%; }
.btn-small { padding: 4px 12px; font-size: 12px; }
.btn-icon {
    background: none;
    border: none;
    cursor: pointer;
    color: var(--color-text-secondary);
    font-size: 18px;
    padding: 4px;
}
.btn-icon:hover { color: var(--color-text); }

/* Cards */
.post-card {
    background: var(--color-surface);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-lg);
    padding: 16px;
    margin-bottom: 12px;
}
.post-card:hover { border-color: var(--color-surface-hover); }
.post-header { display: flex; align-items: center; justify-content: space-between; margin-bottom: 10px; }
.post-author { display: flex; align-items: center; gap: 8px; color: var(--color-text); }
.post-author:hover { text-decoration: none; }
.author-name { font-weight: 600; font-size: 14px; }
.post-time { font-size: 12px; color: var(--color-text-secondary); }
.post-content { margin-bottom: 12px; }
.post-content p { white-space: pre-wrap; word-break: break-word; }
.post-content img { border-radius: var(--radius); margin-top: 8px; }

/* Post Actions */
.post-actions { display: flex; gap: 16px; }
.action-btn {
    display: inline-flex;
    align-items: center;
    gap: 4px;
    background: none;
    border: none;
    color: var(--color-text-secondary);
    cursor: pointer;
    font-size: 14px;
    padding: 4px 8px;
    border-radius: var(--radius);
}
.action-btn:hover { background: var(--color-surface-hover); color: var(--color-text); text-decoration: none; }
.action-btn.active { color: var(--color-primary); }

/* Composer */
.composer-card {
    background: var(--color-surface);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-lg);
    padding: 16px;
    margin-bottom: 20px;
}
.composer textarea {
    width: 100%;
    background: var(--color-bg);
    color: var(--color-text);
    border: 1px solid var(--color-border);
    border-radius: var(--radius);
    padding: 10px 12px;
    font-size: 14px;
    font-family: inherit;
    resize: vertical;
}
.composer textarea:focus { outline: none; border-color: var(--color-primary); }
.composer-actions { display: flex; justify-content: space-between; align-items: center; margin-top: 10px; }
.image-preview { position: relative; display: inline-block; margin-top: 8px; }
.image-preview img { max-height: 200px; border-radius: var(--radius); }
.image-preview .btn-icon { position: absolute; top: 4px; right: 4px; background: rgba(0,0,0,0.6); color: white; border-radius: 50%; width: 24px; height: 24px; }

/* Forms */
.form-group { margin-bottom: 16px; }
.form-group label { display: block; font-size: 13px; font-weight: 600; color: var(--color-text-secondary); margin-bottom: 4px; }
.form-group input[type="text"],
.form-group input[type="email"],
.form-group textarea,
.form-group select {
    width: 100%;
    background: var(--color-bg);
    color: var(--color-text);
    border: 1px solid var(--color-border);
    border-radius: var(--radius);
    padding: 10px 12px;
    font-size: 14px;
    font-family: inherit;
}
.form-group input:focus, .form-group textarea:focus, .form-group select:focus {
    outline: none;
    border-color: var(--color-primary);
}
.checkbox-group label { display: flex; align-items: center; gap: 8px; margin-bottom: 8px; font-weight: 400; }

/* Alerts */
.alert { padding: 10px 16px; border-radius: var(--radius); margin-bottom: 16px; font-size: 14px; }
.alert-error { background: rgba(239,68,68,0.15); color: var(--color-danger); border: 1px solid var(--color-danger); }
.alert-success { background: rgba(34,197,94,0.15); color: var(--color-success); border: 1px solid var(--color-success); }

/* Landing */
.landing { max-width: 400px; margin: 0 auto; padding: 80px 16px; text-align: center; }
.landing-hero h1 { font-size: 1.5rem; font-weight: 700; margin-bottom: 8px; }
.landing-tagline { font-size: 0.9rem; color: var(--color-text-secondary); margin-bottom: 28px; }
.auth-card {
    background: var(--color-surface);
    border: 1px solid var(--color-border);
    border-radius: 10px;
    padding: 40px 32px;
    text-align: left;
}
.auth-card h2 { margin-bottom: 8px; font-size: 1.5rem; font-weight: 700; text-align: center; }
.auth-card .auth-subtitle { color: var(--color-text-secondary); font-size: 0.9rem; text-align: center; margin-bottom: 28px; }
.auth-form { margin-bottom: 0; }
.auth-form label { display: block; font-size: 0.85rem; color: var(--color-text-secondary); margin-bottom: 6px; }
.auth-form input[type="email"] {
    width: 100%;
    padding: 10px 14px;
    background: var(--color-bg);
    border: 1px solid var(--color-border);
    border-radius: 6px;
    color: var(--color-text);
    font-size: 0.95rem;
    outline: none;
    transition: border-color 0.15s;
}
.auth-form input[type="email"]:focus { border-color: var(--color-primary); }
.auth-form input[type="email"]::placeholder { color: var(--color-text-secondary); opacity: 0.5; }
.auth-form .btn { margin-top: 16px; }
.auth-note {
    margin-top: 24px;
    padding-top: 20px;
    border-top: 1px solid var(--color-border);
    font-size: 0.8rem;
    color: var(--color-text-secondary);
    text-align: center;
}
.auth-success { text-align: center; }
.auth-success h2 { color: var(--color-success); margin-bottom: 12px; }
.auth-success p { margin-bottom: 8px; }
.landing-disclosure { margin-top: 24px; font-size: 12px; color: var(--color-text-secondary); }

/* Feed */
.feed-header { display: flex; align-items: center; justify-content: space-between; margin-bottom: 16px; }
.sort-toggle { display: flex; gap: 4px; }

/* Profile */
.profile-page { }
.profile-header { display: flex; gap: 20px; align-items: flex-start; margin-bottom: 32px; flex-wrap: wrap; }
.profile-info { flex: 1; min-width: 200px; }
.profile-info h1 { font-size: 24px; margin-bottom: 2px; }
.profile-username { color: var(--color-text-secondary); font-size: 14px; margin-bottom: 8px; }
.profile-bio { margin-bottom: 8px; }
.profile-stats { display: flex; gap: 16px; font-size: 14px; color: var(--color-text-secondary); }
.profile-actions { display: flex; gap: 8px; align-items: center; }

/* Groups */
.groups-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(280px, 1fr)); gap: 24px; }
.group-card {
    display: flex;
    flex-direction: column;
    gap: 8px;
    background: var(--color-surface);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-lg);
    padding: 16px;
    color: var(--color-text);
}
.group-card:hover { border-color: var(--color-primary); text-decoration: none; }
.group-icon { font-size: 28px; }
.group-card h3 { margin: 0; }
.group-card .text-secondary { margin: 0; }
.group-card-meta { display: flex; gap: 8px; align-items: center; flex-wrap: wrap; margin-top: auto; }
.group-members { font-size: 12px; color: var(--color-text-secondary); }
.group-header { display: flex; justify-content: space-between; align-items: flex-start; margin-bottom: 20px; gap: 16px; }
.group-info { flex: 1; }
.group-info h1 { font-size: 24px; margin-bottom: 4px; }
.category-filter { display: flex; gap: 4px; margin-bottom: 16px; flex-wrap: wrap; }

/* DMs */
.dms-layout { display: grid; grid-template-columns: 280px 1fr; gap: 16px; min-height: 500px; }
.conversation-list {
    background: var(--color-surface);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-lg);
    overflow-y: auto;
    max-height: 600px;
}
.conversation-item {
    display: flex;
    gap: 10px;
    align-items: center;
    padding: 12px;
    border-bottom: 1px solid var(--color-border);
    color: var(--color-text);
}
.conversation-item:hover { background: var(--color-surface-hover); text-decoration: none; }
.conversation-item.active { background: var(--color-surface-hover); }
.conv-info { overflow: hidden; }
.conv-name { font-weight: 600; font-size: 14px; }
.conv-preview { display: block; font-size: 12px; color: var(--color-text-secondary); white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
.message-thread {
    background: var(--color-surface);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-lg);
    display: flex;
    flex-direction: column;
}
.thread-header { padding: 12px 16px; border-bottom: 1px solid var(--color-border); }
.message-list { flex: 1; padding: 16px; overflow-y: auto; max-height: 450px; }
.message { margin-bottom: 12px; display: flex; }
.message.sent { justify-content: flex-end; }
.message-bubble {
    max-width: 70%;
    padding: 8px 14px;
    border-radius: 16px;
    font-size: 14px;
}
.message.received .message-bubble { background: var(--color-bg); }
.message.sent .message-bubble { background: var(--color-primary); color: white; }
.message-time { display: block; font-size: 10px; color: var(--color-text-secondary); margin-top: 2px; }
.message.sent .message-time { color: rgba(255,255,255,0.7); }
.message-composer {
    display: flex;
    gap: 8px;
    padding: 12px;
    border-top: 1px solid var(--color-border);
}
.message-composer input {
    flex: 1;
    background: var(--color-bg);
    color: var(--color-text);
    border: 1px solid var(--color-border);
    border-radius: 20px;
    padding: 8px 16px;
    font-size: 14px;
}
.message-composer input:focus { outline: none; border-color: var(--color-primary); }
.thread-empty { display: flex; align-items: center; justify-content: center; height: 100%; }

/* Notifications */
.notification-item {
    display: flex;
    gap: 10px;
    align-items: center;
    padding: 12px 16px;
    background: var(--color-surface);
    border: 1px solid var(--color-border);
    border-radius: var(--radius);
    margin-bottom: 8px;
}
.notification-item.unread { border-left: 3px solid var(--color-primary); }
.notif-body { flex: 1; }
.notif-body p { font-size: 14px; }
.notif-time { font-size: 11px; color: var(--color-text-secondary); }
.notif-link { font-size: 13px; }

/* Search */
.search-form { display: flex; gap: 8px; margin-bottom: 16px; }
.search-form input {
    flex: 1;
    background: var(--color-surface);
    color: var(--color-text);
    border: 1px solid var(--color-border);
    border-radius: var(--radius);
    padding: 10px 16px;
    font-size: 15px;
}
.search-form input:focus { outline: none; border-color: var(--color-primary); }
.search-tabs { display: flex; gap: 4px; margin-bottom: 16px; }
.user-card {
    display: flex;
    gap: 10px;
    align-items: center;
    padding: 12px;
    background: var(--color-surface);
    border: 1px solid var(--color-border);
    border-radius: var(--radius);
    margin-bottom: 8px;
    color: var(--color-text);
}
.user-card:hover { border-color: var(--color-primary); text-decoration: none; }

/* Onboarding */
.onboarding-page { max-width: 500px; margin: 40px auto; }
.onboarding-card { background: var(--color-surface); border: 1px solid var(--color-border); border-radius: var(--radius-lg); padding: 32px 24px; }
.onboarding-progress { display: flex; gap: 8px; margin-bottom: 24px; }
.onboarding-progress .step { font-size: 12px; color: var(--color-text-secondary); padding: 4px 10px; border-radius: 12px; }
.onboarding-progress .step.active { background: var(--color-primary); color: white; }
.interest-grid { display: grid; grid-template-columns: repeat(2, 1fr); gap: 8px; margin-bottom: 20px; }
.interest-option { display: flex; align-items: center; gap: 8px; padding: 10px; background: var(--color-bg); border-radius: var(--radius); cursor: pointer; }
.interest-option:has(input:checked) { background: var(--color-primary); color: white; }
.interest-option input { display: none; }
.suggested-list { margin-bottom: 20px; }
.suggested-user { display: flex; gap: 10px; align-items: center; padding: 10px; margin-bottom: 4px; border-radius: var(--radius); cursor: pointer; }
.suggested-user:hover { background: var(--color-surface-hover); }

/* Settings */
.settings-page { max-width: 500px; margin: 0 auto; }
.settings-section { margin-bottom: 32px; }
.settings-section h2 { font-size: 18px; margin-bottom: 16px; padding-bottom: 8px; border-bottom: 1px solid var(--color-border); }
.avatar-upload { display: flex; align-items: center; gap: 12px; }

/* Bookmarks */
.bookmarks-page h1 { margin-bottom: 20px; }

/* Dropdown */
.dropdown { position: relative; }
.dropdown-menu {
    display: none;
    position: absolute;
    right: 0;
    top: 100%;
    background: var(--color-surface);
    border: 1px solid var(--color-border);
    border-radius: var(--radius);
    box-shadow: var(--shadow);
    z-index: 50;
    min-width: 120px;
}
.dropdown-menu.show { display: block; }
.dropdown-menu button {
    display: block;
    width: 100%;
    text-align: left;
    padding: 8px 12px;
    background: none;
    border: none;
    color: var(--color-text);
    cursor: pointer;
    font-size: 13px;
}
.dropdown-menu button:hover { background: var(--color-surface-hover); }

/* Empty State */
.empty-state { text-align: center; padding: 40px 16px; color: var(--color-text-secondary); }
.load-more { text-align: center; padding: 16px; }

/* Error Page */
.error-page { text-align: center; padding: 80px 16px; }
.error-page h1 { font-size: 72px; color: var(--color-text-secondary); }
.error-page p { margin: 16px 0 32px; color: var(--color-text-secondary); }

/* Disclaimer Footer */
.disclaimer-footer {
    background: var(--color-surface);
    border-top: 1px solid var(--color-border);
    padding: 12px 20px;
    text-align: center;
    font-size: 11px;
    color: var(--color-text-secondary);
    position: fixed;
    bottom: 0;
    left: 0;
    right: 0;
}

/* Back Link */
.back-link { display: inline-block; margin-bottom: 16px; font-size: 14px; }

/* Inline Form */
.inline-form { display: inline; }

/* Text Utilities */
.text-secondary { color: var(--color-text-secondary); }
mark { background: var(--color-warning); color: #000; padding: 0 2px; border-radius: 2px; }

/* Responsive */
@media (max-width: 768px) {
    .main-nav { padding: 8px 12px; gap: 8px; }
    .nav-links { gap: 0; }
    .nav-link { padding: 6px 8px; font-size: 12px; }
    .dms-layout { grid-template-columns: 1fr; }
    .conversation-list { max-height: 200px; }
    .profile-header { flex-direction: column; align-items: center; text-align: center; }
    .profile-stats { justify-content: center; }
    .groups-grid { grid-template-columns: 1fr; }
}