* { margin: 0; padding: 0; box-sizing: border-box; }
body { font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif; background: #0a0a1a; color: #e4e4e4; min-height: 100vh; display: flex; flex-direction: column; }

nav { background: #12122a; border-bottom: 1px solid #2a2a4a; position: sticky; top: 0; z-index: 100; }
.nav-inner { max-width: 1200px; margin: 0 auto; padding: 1rem 2rem; display: flex; justify-content: space-between; align-items: center; }
.logo { font-size: 1.3rem; font-weight: 700; color: #7c3aed; text-decoration: none; }
.nav-links { display: flex; gap: 2rem; }
.nav-links a { color: #a0a0c0; text-decoration: none; font-size: 0.95rem; }
.nav-links a:hover { color: #7c3aed; }

main { flex: 1; }
.container { max-width: 1200px; margin: 0 auto; padding: 3rem 2rem; }

.hero { text-align: center; padding: 5rem 2rem; background: linear-gradient(135deg, #0a0a1a 0%, #1a1a3e 100%); }
.hero h1 { font-size: 3rem; margin-bottom: 1rem; line-height: 1.2; }
.highlight { color: #7c3aed; }
.hero p { color: #a0a0c0; font-size: 1.2rem; margin-bottom: 2rem; }
.hero-actions { display: flex; gap: 1rem; justify-content: center; }
.hero-actions .btn { padding: 0.8rem 2rem; font-size: 1.1rem; }

.btn { display: inline-block; padding: 0.6rem 1.5rem; border-radius: 8px; text-decoration: none; cursor: pointer; border: none; font-size: 0.95rem; transition: all 0.2s; }
.btn-primary { background: #7c3aed; color: white; }
.btn-primary:hover { background: #6d28d9; }
.btn-secondary { background: transparent; color: #7c3aed; border: 1px solid #7c3aed; }
.btn-secondary:hover { background: #7c3aed22; }
.btn-sm { padding: 0.4rem 1rem; font-size: 0.85rem; }
.btn { background: #2a2a4a; color: #e4e4e4; }
.btn:hover { background: #3a3a5a; }

.features { display: grid; grid-template-columns: repeat(auto-fit, minmax(300px, 1fr)); gap: 1.5rem; padding: 3rem 2rem; max-width: 1200px; margin: 0 auto; }
.feature-card { background: #12122a; border: 1px solid #2a2a4a; border-radius: 12px; padding: 2rem; cursor: pointer; transition: all 0.2s; }
.feature-card:hover { border-color: #7c3aed; transform: translateY(-2px); }
.feature-icon { font-size: 2rem; margin-bottom: 1rem; }
.feature-card h3 { margin-bottom: 0.5rem; }
.feature-card p { color: #a0a0c0; font-size: 0.9rem; line-height: 1.5; }

h1 { margin-bottom: 0.5rem; }
.subtitle { color: #a0a0c0; margin-bottom: 2rem; }

.course-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(300px, 1fr)); gap: 1.5rem; }
.course-card { background: #12122a; border: 1px solid #2a2a4a; border-radius: 12px; padding: 1.5rem; }
.course-card.highlighted { border-color: #7c3aed; }
.course-card h3 { margin-bottom: 0.5rem; }
.course-card p { color: #a0a0c0; font-size: 0.85rem; margin-bottom: 0.8rem; }
.badge { display: inline-block; padding: 0.2rem 0.6rem; border-radius: 4px; font-size: 0.75rem; background: #2a2a4a; color: #7c3aed; margin-bottom: 0.5rem; }
.course-meta { color: #606080; font-size: 0.8rem; margin-bottom: 1rem; }

.chat-container { border: 1px solid #2a2a4a; border-radius: 12px; overflow: hidden; background: #12122a; margin-bottom: 1rem; }
.chat-messages { height: 400px; overflow-y: auto; padding: 1rem; }
.message { margin-bottom: 1rem; display: flex; }
.message.ai { justify-content: flex-start; }
.message.user { justify-content: flex-end; }
.msg-content { max-width: 75%; padding: 0.8rem 1rem; border-radius: 12px; line-height: 1.5; }
.message.ai .msg-content { background: #2a2a4a; color: #e4e4e4; }
.message.user .msg-content { background: #7c3aed; color: white; }
.chat-input { display: flex; border-top: 1px solid #2a2a4a; }
.chat-input input { flex: 1; padding: 1rem; border: none; background: #1a1a2e; color: #e4e4e4; font-size: 1rem; outline: none; }
.chat-input button { padding: 1rem 2rem; background: #7c3aed; color: white; border: none; cursor: pointer; font-size: 1rem; }

.suggestions { display: flex; gap: 0.5rem; flex-wrap: wrap; }
.chip { padding: 0.5rem 1rem; background: #2a2a4a; border: 1px solid #3a3a5a; border-radius: 20px; color: #a0a0c0; cursor: pointer; font-size: 0.85rem; }
.chip:hover { border-color: #7c3aed; color: #7c3aed; }

.tools-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(280px, 1fr)); gap: 1.5rem; margin-bottom: 2rem; }
.tool-card { background: #12122a; border: 1px solid #2a2a4a; border-radius: 12px; padding: 1.5rem; }
.tool-icon { font-size: 2rem; margin-bottom: 0.8rem; }
.tool-card h3 { margin-bottom: 0.5rem; }
.tool-card p { color: #a0a0c0; font-size: 0.85rem; margin-bottom: 1rem; }

.tool-detail { background: #12122a; border: 1px solid #2a2a4a; border-radius: 12px; padding: 2rem; }
.tool-detail h2 { margin-bottom: 1rem; }
.prompt-item { background: #1a1a2e; padding: 1rem; border-radius: 8px; margin-bottom: 0.5rem; border-left: 3px solid #7c3aed; }

.gen-form { display: flex; gap: 0.5rem; margin-bottom: 1rem; flex-wrap: wrap; }
.gen-form input, .gen-form select { padding: 0.6rem 1rem; border-radius: 8px; border: 1px solid #2a2a4a; background: #1a1a2e; color: #e4e4e4; font-size: 0.95rem; flex: 1; min-width: 200px; }
.lesson-output { background: #1a1a2e; padding: 1.5rem; border-radius: 8px; line-height: 1.8; }

footer { text-align: center; padding: 2rem; color: #606080; font-size: 0.85rem; border-top: 1px solid #1a1a2e; }
footer a { color: #7c3aed; text-decoration: none; }

input:focus, select:focus { outline: none; border-color: #7c3aed; }
::-webkit-scrollbar { width: 8px; }
::-webkit-scrollbar-track { background: #0a0a1a; }
::-webkit-scrollbar-thumb { background: #2a2a4a; border-radius: 4px; }

.oss-links { display: flex; gap: 1rem; flex-wrap: wrap; margin-top: 1rem; }
textarea { width: 100%; padding: 0.8rem; border-radius: 8px; border: 1px solid #2a2a4a; background: #1a1a2e; color: #e4e4e4; font-family: monospace; font-size: 0.9rem; margin-bottom: 0.5rem; }
.model-status { padding: 0.6rem 1rem; border-radius: 8px; background: #12122a; border: 1px solid #2a2a4a; margin-bottom: 1rem; font-size: 0.9rem; color: #f59e0b; }
.model-status.ready { color: #22c55e; border-color: #22c55e33; }