:root {
    --bg-deep: #0e0a08;
    --bg-surface: rgba(40, 30, 25, 0.85);
    --accent-amber: #f59e0b;
    --accent-warm: #ef4444;
    --text-main: #fef3c7;
    --text-dim: #a78b6a;
    --glass-border: rgba(255, 200, 150, 0.15);
    --glass-highlight: rgba(255, 200, 150, 0.05);
    --primary-gradient: linear-gradient(135deg, #f59e0b 0%, #ef4444 100%);
    --msg-user-bg: rgba(245, 158, 11, 0.12);
    --msg-assistant-bg: rgba(255, 255, 255, 0.04);
}
* { box-sizing: border-box; margin: 0; padding: 0; }
body { font-family: 'Inter', sans-serif; background-color: var(--bg-deep); color: var(--text-main); line-height: 1.6; overflow-x: hidden; }
h1, h2, h3, h4 { font-family: 'Playfair Display', serif; font-weight: 700; }

.glow-bg {
    position: fixed; top: 0; left: 0; width: 100%; height: 100%; z-index: -1;
    background: radial-gradient(circle at 10% 20%, rgba(245,158,11,0.06) 0%, transparent 40%),
                radial-gradient(circle at 90% 80%, rgba(239,68,68,0.06) 0%, transparent 40%);
}

.navbar {
    display: flex; justify-content: space-between; align-items: center; padding: 20px 5%;
    position: sticky; top: 0; z-index: 100; backdrop-filter: blur(10px);
    background: rgba(14,10,8,0.8); border-bottom: 1px solid var(--glass-border);
}
.nav-logo { font-family: 'Playfair Display', serif; font-size: 1.5rem; font-weight: 700; letter-spacing: -1px; }
.nav-logo span { color: var(--accent-amber); }
.nav-links a { color: var(--text-dim); text-decoration: none; margin-left: 25px; font-size: 0.9rem; transition: color 0.3s; }
.nav-links a:hover { color: var(--accent-amber); }
.back-link { color: var(--accent-amber) !important; font-weight: 600; }
.download-chat-link { cursor: pointer; font-weight: 600; color: var(--accent-amber) !important; }

html, body { height: 100%; }

.chat-section { padding: 30px 5%; max-width: 1800px; margin: 0 auto; display: block; min-height: 100vh; }
.chat-container {
    display: flex; flex-direction: column; min-height: 500px;
    width: 1100px;
    position: relative;
    left: 50%;
    transform: translateX(-50%);
    background: var(--bg-surface); border: 1px solid var(--glass-border); border-radius: 32px;
    backdrop-filter: blur(20px); overflow: hidden;
}
.chat-container .resize-handle {
    position: absolute; bottom: 0; right: 0; width: 20px; height: 20px;
    cursor: nwse-resize; z-index: 10;
    background: linear-gradient(135deg, transparent 40%, var(--accent-amber) 40%, var(--accent-amber) 60%, transparent 60%);
    opacity: 0.4;
}
.chat-container .resize-handle:hover { opacity: 0.8; }

.chat-tabs { display: flex; background: rgba(0,0,0,0.3); border-bottom: 1px solid var(--glass-border); flex-shrink: 0; border-radius: 32px 32px 0 0; }
.chat-tabs .tab-btn {
    flex: 1; padding: 16px 18px; border: none; background: none; cursor: pointer;
    color: var(--text-dim); font-weight: 600; transition: all 0.3s; font-family: 'Inter', sans-serif;
}
.chat-tabs .tab-btn.active { color: white; background: rgba(255,255,255,0.05); box-shadow: inset 0 -3px 0 var(--accent-amber); }

.chat-panel { display: none; flex-direction: column; flex: 1; min-height: 200px; }
.chat-panel.active { display: flex; }

.chat-intro { padding: 16px 24px; border-bottom: 1px solid var(--glass-border); flex-shrink: 0; }
.chat-intro h3 { font-size: 1.3rem; margin-bottom: 6px; }
.chat-intro p { color: var(--text-dim); font-size: 0.85rem; margin-bottom: 12px; }
.upload-row { display: flex; gap: 10px; align-items: center; flex-wrap: wrap; }
.upload-row .drop-zone { flex: 1; min-width: 180px; padding: 10px 18px; }
.upload-row .studio-btn { flex-shrink: 0; padding: 10px 22px; font-size: 0.85rem; display: flex; align-items: center; gap: 6px; }
.file-list { margin-top: 6px; }

.chat-messages {
    flex: 1; overflow-y: auto; padding: 20px 30px;
    display: flex; flex-direction: column; gap: 16px;
}
.message { display: flex; gap: 12px; animation: fadeIn 0.3s ease; }
.message.user { flex-direction: row-reverse; }
.msg-avatar { width: 36px; height: 36px; border-radius: 50%; display: flex; align-items: center; justify-content: center; font-size: 1.1rem; flex-shrink: 0; }
.message.assistant .msg-avatar { background: rgba(245,158,11,0.15); }
.message.user .msg-avatar { background: rgba(239,68,68,0.15); }
.msg-content {
    max-width: 90%; padding: 18px 24px; border-radius: 16px; font-size: 0.95rem; line-height: 1.7;
    word-wrap: break-word; overflow-wrap: break-word; hyphens: auto;
}
.message.assistant .msg-content { background: var(--msg-assistant-bg); border: 1px solid var(--glass-border); border-top-left-radius: 4px; }
.message.user .msg-content { background: var(--msg-user-bg); border: 1px solid rgba(245,158,11,0.2); border-top-right-radius: 4px; }
.msg-content p { margin-bottom: 6px; }
.msg-content p:last-child { margin-bottom: 0; }
.msg-content strong { color: var(--accent-amber); }
.msg-content .msg-label { font-size: 0.7rem; color: var(--text-dim); margin-top: 6px; display: block; }

.chat-input-area {
    padding: 12px 24px; border-top: 1px solid var(--glass-border);
    display: flex; gap: 10px; align-items: center; background: rgba(0,0,0,0.2); flex-shrink: 0;
}
.chat-input {
    flex: 1; background: rgba(0,0,0,0.3); border: 1px solid var(--glass-border);
    border-radius: 12px; padding: 14px 18px; color: white; font-family: 'Inter', sans-serif;
    font-size: 0.95rem; resize: vertical; outline: none; transition: border-color 0.3s;
    min-height: 50px; max-height: 150px; line-height: 1.5;
}
.chat-input:focus { border-color: var(--accent-amber); }
.chat-input::placeholder { color: var(--text-dim); }
.send-btn {
    background: var(--primary-gradient); color: white; border: none; padding: 14px 28px;
    border-radius: 12px; font-weight: 600; cursor: pointer; transition: all 0.3s; flex-shrink: 0;
}
.send-btn:hover { transform: scale(1.05); box-shadow: 0 0 15px rgba(245,158,11,0.3); }
.send-btn:disabled { opacity: 0.4; cursor: not-allowed; transform: none; box-shadow: none; }

.loader-ring {
    width: 22px; height: 22px; border: 2px solid rgba(245,158,11,0.2);
    border-top: 2px solid var(--accent-amber); border-radius: 50%; animation: spin 0.8s linear infinite; flex-shrink: 0;
}
.loader-ring.hidden { display: none; }
@keyframes spin { 0% { transform: rotate(0deg); } 100% { transform: rotate(360deg); } }
@keyframes fadeIn { from { opacity: 0; transform: translateY(8px); } to { opacity: 1; transform: translateY(0); } }

.drop-zone {
    border: 1px solid var(--glass-border); border-radius: 12px; padding: 20px 30px;
    text-align: center; background: var(--bg-surface); backdrop-filter: blur(10px);
    transition: all 0.3s ease; cursor: pointer; position: relative; overflow: hidden;
}
.drop-zone::before {
    content: ''; position: absolute; top: 0; left: 0; right: 0; bottom: 0; border-radius: 12px;
    padding: 1px; background: linear-gradient(135deg, rgba(245,158,11,0.2), rgba(239,68,68,0.2));
    -webkit-mask: linear-gradient(#fff 0 0) content-box, linear-gradient(#fff 0 0);
    -webkit-mask-composite: xor; mask-composite: exclude;
    pointer-events: none; opacity: 0; transition: opacity 0.3s ease;
}
.drop-zone:hover::before, .drop-zone.drag-over::before { opacity: 1; }
.drop-zone:hover { border-color: transparent; }
.drop-zone.drag-over { border-color: transparent; background: rgba(245,158,11,0.08); box-shadow: 0 0 30px rgba(245,158,11,0.15); }
.file-label { color: var(--text-dim); font-size: 0.85rem; }
input[type="file"] { display: none; }
.file-list { display: flex; flex-direction: column; gap: 6px; }
.file-item { background: var(--bg-surface); padding: 6px 12px; border-radius: 6px; font-size: 0.8rem; border: 1px solid var(--glass-border); }

footer { padding: 30px 5%; border-top: 1px solid var(--glass-border); text-align: center; background: rgba(0,0,0,0.4); flex-shrink: 0; }
.footer-logo { font-family: 'Playfair Display', serif; font-size: 1.1rem; margin-bottom: 8px; }
.footer-logo span { color: var(--accent-amber); }
.footer-content p { color: var(--text-dim); font-size: 0.8rem; }

@media (max-width: 768px) {
    .chat-section { height: calc(100vh - 100px); padding: 15px 3%; }
    .chat-messages { padding: 15px; }
    .msg-content { max-width: 85%; }
    .chat-input-area { padding: 10px 15px; }
    .upload-row { flex-direction: column; }
    .chat-container { min-width: 0; }
}