:root {
    --bg-primary: #0d1117;
    --bg-secondary: #161b22;
    --bg-tertiary: #1c2128;
    --bg-msg-user: #1a2332;
    --bg-msg-oswyn: #121a12;
    --border: #30363d;
    --text-primary: #e6edf3;
    --text-secondary: #8b949e;
    --text-muted: #484f58;
    --green: #3fb950;
    --green-dim: rgba(63, 185, 80, 0.15);
    --green-glow: rgba(63, 185, 80, 0.3);
    --purple: #bc8cff;
    --accent: #58a6ff;
    --red: #f85149;
    --orange: #f0883e;
    --cyan: #53d8fb;
    --font-mono: 'JetBrains Mono', 'Fira Code', 'Cascadia Code', 'Menlo', 'Consolas', monospace;
    --font-sans: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Noto Sans', Helvetica, Arial, sans-serif;
}

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

html, body {
    height: 100%;
    background: var(--bg-primary);
    color: var(--text-primary);
    font-family: var(--font-sans);
    overflow: hidden;
}

/* ---- Layout ---- */
.app {
    display: flex;
    flex-direction: column;
    height: 100vh;
}

/* ---- Header ---- */
header {
    height: 52px;
    background: var(--bg-secondary);
    border-bottom: 1px solid var(--border);
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 0 16px;
    flex-shrink: 0;
}

.header-left {
    display: flex;
    align-items: center;
    gap: 10px;
}

.logo {
    height: 32px;
    width: 32px;
    object-fit: contain;
    border-radius: 8px;
    filter: drop-shadow(0 0 6px var(--green-glow));
}

header h1 {
    font-size: 1.1rem;
    font-weight: 700;
    color: var(--green);
}

.badge {
    font-size: 0.65rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    color: var(--green);
    background: var(--green-dim);
    border: 1px solid rgba(63, 185, 80, 0.25);
    padding: 2px 8px;
    border-radius: 10px;
}

.header-right { display: flex; align-items: center; gap: 8px; }

.btn-ghost {
    display: flex;
    align-items: center;
    gap: 5px;
    background: transparent;
    color: var(--text-secondary);
    border: 1px solid var(--border);
    padding: 5px 10px;
    font-family: var(--font-sans);
    font-size: 0.78rem;
    border-radius: 6px;
    cursor: pointer;
    text-decoration: none;
    transition: all 0.15s;
}
.btn-ghost:hover { color: var(--text-primary); border-color: var(--text-muted); }

/* ---- Chat area ---- */
.chat {
    flex: 1;
    overflow-y: auto;
    padding: 0;
    display: flex;
    flex-direction: column;
}

.chat-spacer {
    flex: 1;
}

/* ---- Welcome screen ---- */
.welcome {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    text-align: center;
    padding: 60px 20px;
    min-height: 100%;
}

.welcome-img {
    width: 120px;
    height: 120px;
    object-fit: contain;
    filter: drop-shadow(0 0 20px var(--green-glow));
    margin-bottom: 20px;
    animation: float 3s ease-in-out infinite;
}

@keyframes float {
    0%, 100% { transform: translateY(0); }
    50% { transform: translateY(-8px); }
}

.welcome h2 {
    font-size: 1.5rem;
    color: var(--green);
    margin-bottom: 8px;
}

.welcome p {
    color: var(--text-secondary);
    max-width: 480px;
    line-height: 1.6;
    margin-bottom: 24px;
}

.suggestions {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
    justify-content: center;
    max-width: 560px;
}

.suggestion {
    background: var(--bg-tertiary);
    border: 1px solid var(--border);
    color: var(--text-secondary);
    padding: 8px 14px;
    font-family: var(--font-sans);
    font-size: 0.82rem;
    border-radius: 20px;
    cursor: pointer;
    transition: all 0.15s;
}
.suggestion:hover {
    color: var(--green);
    border-color: var(--green);
    background: var(--green-dim);
}

/* ---- Messages ---- */
.message {
    padding: 16px 20px;
    border-bottom: 1px solid rgba(48, 54, 61, 0.4);
    display: flex;
    gap: 14px;
    max-width: 820px;
    margin: 0 auto;
    width: 100%;
}

.message.user { background: var(--bg-msg-user); }
.message.assistant { background: var(--bg-msg-oswyn); }

.msg-avatar {
    width: 32px;
    height: 32px;
    border-radius: 8px;
    flex-shrink: 0;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.2rem;
}
.msg-avatar.user-avatar {
    background: var(--bg-tertiary);
    border: 1px solid var(--border);
    color: var(--text-secondary);
}
.msg-avatar img {
    width: 32px;
    height: 32px;
    object-fit: contain;
    border-radius: 8px;
    filter: drop-shadow(0 0 4px var(--green-glow));
}

.msg-body {
    flex: 1;
    min-width: 0;
    line-height: 1.65;
    font-size: 0.92rem;
}

.msg-body p { margin-bottom: 8px; }
.msg-body p:last-child { margin-bottom: 0; }

.msg-body code {
    background: var(--bg-tertiary);
    padding: 2px 6px;
    border-radius: 4px;
    font-family: var(--font-mono);
    font-size: 0.85em;
    color: var(--cyan);
}

.msg-body .code-block {
    position: relative;
    margin: 10px 0;
}

.msg-body .code-block .copy-btn {
    position: absolute;
    top: 8px;
    right: 8px;
    background: var(--bg-tertiary);
    color: var(--text-secondary);
    border: 1px solid var(--border);
    border-radius: 4px;
    padding: 3px 10px;
    font-size: 0.75rem;
    font-family: var(--font-sans);
    cursor: pointer;
    opacity: 0;
    transition: opacity 0.15s, background 0.15s, color 0.15s;
    z-index: 1;
}

.msg-body .code-block:hover .copy-btn {
    opacity: 1;
}

.msg-body .code-block .copy-btn:hover {
    background: var(--border);
    color: var(--text-primary);
}

.msg-body .code-block .copy-btn.copied {
    color: var(--green);
    opacity: 1;
}

.msg-body pre {
    background: var(--bg-primary);
    border: 1px solid var(--border);
    border-radius: 8px;
    padding: 14px 16px;
    margin: 0;
    overflow-x: auto;
    font-size: 0.85rem;
    line-height: 1.5;
}

.msg-body pre code {
    background: transparent;
    padding: 0;
    color: var(--text-primary);
}

.msg-body strong { color: var(--green); font-weight: 600; }
.msg-body em { color: var(--text-secondary); }
.msg-body a { color: var(--accent); text-decoration: none; }
.msg-body a:hover { text-decoration: underline; }

.msg-body ul, .msg-body ol {
    margin: 8px 0;
    padding-left: 20px;
}
.msg-body li { margin-bottom: 4px; }

.msg-body h3 {
    font-size: 0.95rem;
    color: var(--green);
    margin: 12px 0 6px;
}

/* ---- Typing indicator ---- */
.typing {
    display: flex;
    gap: 4px;
    padding: 4px 0;
}
.typing span {
    width: 6px;
    height: 6px;
    background: var(--green);
    border-radius: 50%;
    animation: blink 1.4s infinite both;
}
.typing span:nth-child(2) { animation-delay: 0.2s; }
.typing span:nth-child(3) { animation-delay: 0.4s; }

@keyframes blink {
    0%, 80%, 100% { opacity: 0.2; }
    40% { opacity: 1; }
}

/* ---- Input area ---- */
.input-area {
    padding: 12px 16px 10px;
    background: var(--bg-secondary);
    border-top: 1px solid var(--border);
    flex-shrink: 0;
}

.input-wrap {
    display: flex;
    align-items: center;
    gap: 8px;
    max-width: 800px;
    margin: 0 auto;
    background: var(--bg-primary);
    border: 1px solid var(--border);
    border-radius: 12px;
    padding: 6px 12px;
    transition: border-color 0.15s;
}
.input-wrap:focus-within { border-color: var(--green); }

#user-input {
    flex: 1;
    background: transparent;
    border: none;
    outline: none;
    color: var(--text-primary);
    font-family: var(--font-sans);
    font-size: 0.9rem;
    line-height: 1.5;
    resize: none;
    min-height: 0;
    height: auto;
    max-height: 150px;
    overflow-y: hidden;
}

.btn-send {
    background: var(--green);
    border: none;
    color: #fff;
    width: 34px;
    height: 34px;
    border-radius: 8px;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    flex-shrink: 0;
    transition: opacity 0.15s;
}
.btn-send:hover { opacity: 0.85; }
.btn-send:disabled { opacity: 0.3; cursor: not-allowed; }

.input-hint {
    display: block;
    text-align: center;
    font-size: 0.7rem;
    color: var(--text-muted);
    margin-top: 6px;
}

/* ---- Settings modal ---- */
.modal-overlay {
    display: none;
    position: fixed;
    inset: 0;
    background: rgba(0,0,0,0.6);
    z-index: 100;
    align-items: center;
    justify-content: center;
}
.modal-overlay.open { display: flex; }

.modal {
    background: var(--bg-secondary);
    border: 1px solid var(--border);
    border-radius: 12px;
    width: 420px;
    max-width: 90vw;
    box-shadow: 0 16px 48px rgba(0,0,0,0.4);
}

.modal-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 16px 20px;
    border-bottom: 1px solid var(--border);
}
.modal-header h2 { font-size: 1rem; color: var(--text-primary); }
.modal-close {
    background: none;
    border: none;
    color: var(--text-secondary);
    font-size: 1.4rem;
    cursor: pointer;
    padding: 0 4px;
}
.modal-close:hover { color: var(--text-primary); }

.modal-body { padding: 20px; }

.field-label {
    display: block;
    font-size: 0.8rem;
    font-weight: 600;
    color: var(--text-secondary);
    margin-bottom: 6px;
    margin-top: 14px;
}
.field-label:first-child { margin-top: 0; }

.field-hint {
    display: block;
    font-size: 0.72rem;
    color: var(--text-muted);
    margin-top: 4px;
}

.modal-body input,
.modal-body select {
    width: 100%;
    background: var(--bg-primary);
    border: 1px solid var(--border);
    color: var(--text-primary);
    padding: 8px 12px;
    font-family: var(--font-sans);
    font-size: 0.85rem;
    border-radius: 6px;
    outline: none;
}
.modal-body input:focus,
.modal-body select:focus { border-color: var(--green); }

.btn-primary {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 5px;
    background: var(--green);
    color: #fff;
    border: none;
    padding: 8px 16px;
    font-family: var(--font-sans);
    font-size: 0.85rem;
    font-weight: 600;
    border-radius: 6px;
    cursor: pointer;
    transition: opacity 0.15s;
}
.btn-primary:hover { opacity: 0.9; }

/* ---- Error banner ---- */
.error-banner {
    background: rgba(248, 81, 73, 0.1);
    border: 1px solid rgba(248, 81, 73, 0.3);
    color: var(--red);
    padding: 10px 16px;
    margin: 8px 20px;
    border-radius: 8px;
    font-size: 0.85rem;
    max-width: 800px;
    margin-left: auto;
    margin-right: auto;
}

/* ---- Scrollbar ---- */
::-webkit-scrollbar { width: 6px; }
::-webkit-scrollbar-track { background: transparent; }
::-webkit-scrollbar-thumb { background: var(--border); border-radius: 3px; }
::-webkit-scrollbar-thumb:hover { background: var(--text-muted); }

/* ---- Responsive ---- */
@media (max-width: 640px) {
    .message { padding: 12px 14px; }
    .welcome { padding: 40px 16px; }
    .suggestions { flex-direction: column; align-items: stretch; }
    header h1 { font-size: 1rem; }
    .badge { display: none; }
}