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

:root {
  --bg: #0d0d0d;
  --surface: #1a1a1a;
  --border: #333;
  --text: #e0e0e0;
  --text-secondary: #888;
  --accent: #00e676;
  --font: 'SF Mono', 'Fira Code', 'Cascadia Code', 'JetBrains Mono', ui-monospace, monospace;
}

body {
  background: var(--bg);
  color: var(--text);
  font-family: var(--font);
  font-size: 14px;
  line-height: 1.6;
  min-height: 100dvh;
  -webkit-font-smoothing: antialiased;
}

/* ── Mode Toggle ── */
.mode-input #chat { display: none; }
.mode-chat #landing { display: none; }

/* ── Landing ── */
#landing {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  min-height: 100dvh;
  padding: 20px;
}

.logo {
  color: var(--accent);
  font-size: 26px;
  font-weight: 700;
  letter-spacing: 1px;
  margin-bottom: 8px;
}

.howto-link {
  display: inline-block;
  color: var(--text-secondary);
  text-decoration: none;
  font-size: 12px;
  margin-top: 16px;
  padding: 6px 12px;
  border: 1px solid var(--border);
  border-radius: 6px;
  transition: all 0.2s;
}

.howto-link:hover {
  color: var(--accent);
  border-color: var(--accent);
}

.tagline {
  color: var(--text-secondary);
  font-size: 13px;
  text-align: center;
  margin-bottom: 32px;
}

.input-box {
  width: 100%;
  max-width: 500px;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 16px;
}

.input-box textarea {
  width: 100%;
  min-height: 120px;
  background: transparent;
  border: none;
  color: var(--text);
  font-family: var(--font);
  font-size: 14px;
  line-height: 1.6;
  resize: vertical;
  outline: none;
}

.input-box textarea::placeholder {
  color: var(--text-secondary);
}

.input-actions {
  display: flex;
  gap: 8px;
  margin-top: 12px;
  align-items: center;
}

.btn-secondary {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 8px;
  color: var(--accent);
  font-family: var(--font);
  font-size: 13px;
  padding: 8px 12px;
  cursor: pointer;
}

.btn-secondary:disabled {
  opacity: 0.4;
  cursor: not-allowed;
}

.btn-primary {
  background: var(--accent);
  border: none;
  border-radius: 8px;
  color: var(--bg);
  font-family: var(--font);
  font-size: 13px;
  font-weight: 700;
  padding: 8px 16px;
  cursor: pointer;
  margin-left: auto;
}

.btn-primary:disabled {
  opacity: 0.3;
  cursor: not-allowed;
}

.hints {
  color: #555;
  font-size: 11px;
  text-align: center;
  margin-top: 16px;
}

/* ── Chat ── */
#chat {
  display: flex;
  flex-direction: column;
  height: 100dvh;
}

.chat-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 12px 20px;
  border-bottom: 1px solid var(--border);
  flex-shrink: 0;
}

.logo-small {
  color: var(--accent);
  font-size: 16px;
  font-weight: 700;
  letter-spacing: 1px;
  text-decoration: none;
}

.btn-new {
  background: none;
  border: 1px solid var(--border);
  border-radius: 6px;
  color: var(--text-secondary);
  font-family: var(--font);
  font-size: 11px;
  padding: 4px 10px;
  cursor: pointer;
}

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

#messages {
  flex: 1;
  overflow-y: auto;
  padding: 16px 20px;
}

/* ── Messages ── */
.message {
  margin-bottom: 16px;
}

.user-message {
  background: var(--surface);
  border-radius: 12px;
  padding: 12px 16px;
  font-size: 13px;
  color: #aaa;
  margin-left: 40px;
  border-left: 3px solid var(--border);
  white-space: pre-wrap;
  word-break: break-word;
}

.assistant-message {
  border-left: 3px solid var(--accent);
  padding-left: 16px;
}

.message-label {
  color: var(--accent);
  font-size: 11px;
  letter-spacing: 2px;
  margin-bottom: 8px;
}

.message-content {
  font-size: 13px;
  line-height: 1.7;
  word-break: break-word;
}

.message-content strong {
  color: var(--accent);
}

/* ── Streaming Cursor ── */
.cursor {
  color: var(--accent);
  animation: blink 1s infinite;
}

@keyframes blink {
  0%, 50% { opacity: 1; }
  51%, 100% { opacity: 0; }
}

/* ── Collapsible Analysis ── */
.collapse-toggle {
  color: var(--accent);
  font-size: 12px;
  cursor: pointer;
  padding: 4px 0;
  margin-bottom: 8px;
}

.collapse-toggle:hover {
  text-decoration: underline;
}

.collapsed .message-content {
  display: none;
}

/* ── Error ── */
.error {
  color: #ff5252;
}

/* ── Chat Input Bar ── */
.chat-input-bar {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 12px 20px;
  border-top: 1px solid var(--border);
  background: var(--bg);
  flex-shrink: 0;
}

.chat-input-bar input {
  flex: 1;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 24px;
  padding: 10px 16px;
  color: var(--text);
  font-family: var(--font);
  font-size: 13px;
  outline: none;
}

.chat-input-bar input:focus {
  border-color: var(--accent);
}

.chat-input-bar input::placeholder {
  color: #555;
}

.chat-input-bar button {
  background: none;
  border: none;
  color: var(--accent);
  font-size: 20px;
  cursor: pointer;
  padding: 4px 8px;
}

/* ── How-To Page ── */
#howto {
  min-height: 100dvh;
  display: flex;
  flex-direction: column;
}

.howto-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 12px 20px;
  border-bottom: 1px solid var(--border);
  position: sticky;
  top: 0;
  background: var(--bg);
  z-index: 10;
}

.howto-content {
  max-width: 720px;
  width: 100%;
  margin: 0 auto;
  padding: 24px 20px 60px;
}

.howto-content h1 {
  color: var(--accent);
  font-size: 22px;
  font-weight: 700;
  letter-spacing: 1px;
  margin-bottom: 16px;
}

.howto-content h2 {
  color: var(--text);
  font-size: 18px;
  font-weight: 700;
  margin-bottom: 12px;
  margin-top: 0;
}

.howto-content h3 {
  color: var(--accent);
  font-size: 14px;
  font-weight: 700;
  margin: 16px 0 8px;
  letter-spacing: 1px;
}

.howto-content p {
  font-size: 13px;
  line-height: 1.7;
  margin-bottom: 12px;
  color: var(--text);
}

.howto-content ol,
.howto-content ul {
  margin: 8px 0 16px 20px;
  font-size: 13px;
  line-height: 1.8;
}

.howto-content li {
  margin-bottom: 6px;
}

.howto-content code {
  background: var(--surface);
  padding: 2px 6px;
  border-radius: 4px;
  font-size: 12px;
  color: var(--accent);
}

.howto-content a {
  color: var(--accent);
  text-decoration: underline;
}

.howto-intro {
  color: var(--text-secondary);
  font-size: 13px;
  margin-bottom: 24px;
  padding: 12px 16px;
  background: var(--surface);
  border-left: 3px solid var(--accent);
  border-radius: 0 8px 8px 0;
}

.howto-nav {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
  margin-bottom: 24px;
  padding-bottom: 16px;
  border-bottom: 1px solid var(--border);
}

.howto-nav a {
  font-size: 11px;
  padding: 4px 10px;
  border: 1px solid var(--border);
  border-radius: 4px;
  text-decoration: none;
  color: var(--text-secondary);
}

.howto-nav a:hover {
  color: var(--accent);
  border-color: var(--accent);
}

.howto-section {
  margin-bottom: 32px;
  padding: 20px;
  background: var(--surface);
  border-radius: 12px;
  border: 1px solid var(--border);
}

.howto-section.best {
  border-color: var(--accent);
}

.howto-section.dating {
  border-color: #444;
}

.howto-badge {
  display: inline-block;
  font-size: 11px;
  color: var(--accent);
  background: rgba(0, 230, 118, 0.1);
  padding: 4px 10px;
  border-radius: 4px;
  margin-bottom: 12px;
  letter-spacing: 1px;
}

.dating-badge {
  color: #ff8a8a;
  background: rgba(255, 138, 138, 0.1);
}

.howto-tip {
  margin-top: 12px;
  padding: 10px 14px;
  background: var(--bg);
  border-left: 3px solid var(--accent);
  border-radius: 0 6px 6px 0;
  font-size: 12px;
  color: var(--text-secondary);
}

.howto-content blockquote {
  border-left: 3px solid var(--accent);
  padding: 10px 16px;
  margin: 12px 0;
  font-style: italic;
  color: var(--text-secondary);
  background: var(--bg);
  border-radius: 0 6px 6px 0;
}

.howto-cta {
  margin-top: 32px;
  text-align: center;
}

.btn-primary-link {
  display: inline-block;
  background: var(--accent);
  color: var(--bg) !important;
  padding: 12px 24px;
  border-radius: 8px;
  font-weight: 700;
  text-decoration: none !important;
  font-size: 14px;
}

/* ── Responsive ── */
@media (min-width: 768px) {
  #messages {
    max-width: 700px;
    margin: 0 auto;
    width: 100%;
  }

  .chat-input-bar {
    max-width: 700px;
    margin: 0 auto;
    width: 100%;
  }
}