/* =========================================================
   XXIU — Ask Anything
   Structure styles only. No functional logic here.
   ========================================================= */

:root {
  --bg: #0b0d12;
  --bg-soft: #12151d;
  --surface: rgba(255, 255, 255, 0.04);
  --surface-hover: rgba(255, 255, 255, 0.07);
  --border: rgba(255, 255, 255, 0.1);
  --text: #f2f4f8;
  --text-dim: #9aa3b2;
  --accent: #4d7cff;
  --accent-soft: rgba(77, 124, 255, 0.16);
  --radius-lg: 20px;
  --radius-md: 14px;
  --font: "Inter", "SF Pro Display", -apple-system, "Segoe UI", system-ui, sans-serif;
}

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

html {
  scroll-behavior: smooth;
}

body {
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  background: var(--bg);
  color: var(--text);
  font-family: var(--font);
  -webkit-font-smoothing: antialiased;
}

/* ---------- Header ---------- */

.site-header {
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 24px 32px;
  border-bottom: 1px solid var(--border);
  backdrop-filter: blur(12px);
  background: rgba(11, 13, 18, 0.6);
  position: sticky;
  top: 0;
  z-index: 10;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  text-decoration: none;
  color: var(--text);
}

.brand-mark {
  width: 22px;
  height: 22px;
  color: var(--accent);
}

.brand-name {
  font-size: 18px;
  font-weight: 700;
  letter-spacing: 0.22em;
}

/* ---------- Main layout ---------- */

.app-main {
  flex: 1;
  width: 100%;
  max-width: 720px;
  margin: 0 auto;
  padding: 64px 24px 48px;
  display: flex;
  flex-direction: column;
  gap: 40px;
}

/* ---------- Intro ---------- */

.intro {
  position: relative;
  text-align: center;
}

.intro-glow {
  position: absolute;
  top: -120px;
  left: 50%;
  transform: translateX(-50%);
  width: 420px;
  height: 260px;
  background: radial-gradient(ellipse at center, var(--accent-soft), transparent 70%);
  pointer-events: none;
}

.eyebrow {
  font-size: 13px;
  font-weight: 600;
  letter-spacing: 0.28em;
  text-transform: uppercase;
  color: var(--accent);
  margin-bottom: 16px;
}

.intro-title {
  font-size: clamp(36px, 6vw, 56px);
  font-weight: 800;
  line-height: 1.1;
  letter-spacing: -0.02em;
}

.intro-sub {
  margin-top: 16px;
  font-size: 17px;
  color: var(--text-dim);
}

/* ---------- Question form ---------- */

.ask-section {
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.question-form {
  display: flex;
  gap: 12px;
  align-items: stretch;
}

.input-wrap {
  flex: 1;
  position: relative;
  display: flex;
  align-items: center;
}

.input-icon {
  position: absolute;
  left: 18px;
  width: 18px;
  height: 18px;
  color: var(--text-dim);
  pointer-events: none;
}

.question-input {
  width: 100%;
  padding: 18px 20px 18px 50px;
  font-size: 16px;
  font-family: inherit;
  color: var(--text);
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  outline: none;
  transition: border-color 0.2s ease, background 0.2s ease, box-shadow 0.2s ease;
}

.question-input::placeholder {
  color: var(--text-dim);
}

.question-input:focus {
  border-color: var(--accent);
  background: var(--surface-hover);
  box-shadow: 0 0 0 4px var(--accent-soft);
}

.ask-button {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  padding: 0 28px;
  font-size: 16px;
  font-weight: 600;
  font-family: inherit;
  color: #fff;
  background: var(--accent);
  border: none;
  border-radius: var(--radius-md);
  cursor: pointer;
  transition: transform 0.15s ease, filter 0.15s ease;
}

.ask-button:hover {
  filter: brightness(1.1);
}

.ask-button:active {
  transform: scale(0.97);
}

.button-arrow {
  width: 16px;
  height: 16px;
}

.hint {
  font-size: 13px;
  color: var(--text-dim);
  text-align: center;
}

/* ---------- Answer area ---------- */

.answer-section {
  display: flex;
  flex-direction: column;
}

.answer-box {
  min-height: 220px;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 32px;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
}

.answer-placeholder {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 14px;
  text-align: center;
}

.answer-icon {
  width: 30px;
  height: 30px;
  color: var(--text-dim);
  opacity: 0.7;
}

.placeholder-text {
  font-size: 15px;
  color: var(--text-dim);
}

.answer-content {
  width: 100%;
  font-size: 16px;
  line-height: 1.7;
  color: var(--text);
  white-space: pre-wrap;
  word-break: break-word;
}

/* ---------- Footer ---------- */

.site-footer {
  padding: 20px 24px;
  text-align: center;
  border-top: 1px solid var(--border);
  font-size: 13px;
  color: var(--text-dim);
}

/* ---------- Responsive ---------- */

@media (max-width: 560px) {
  .app-main {
    padding: 48px 16px 32px;
    gap: 32px;
  }

  .question-form {
    flex-direction: column;
  }

  .ask-button {
    justify-content: center;
    padding: 16px 24px;
  }

  .answer-box {
    min-height: 160px;
    padding: 24px;
  }
}