/* ========================================
   ChineseAI Master - Soft White Botanical Theme
   Tông trắng nhẹ nhàng với hoa lá
   ======================================== */

@import url('https://fonts.googleapis.com/css2?family=Inter:wght@300;400;500;600;700&family=Noto+Sans+SC:wght@300;400;500;600;700&family=Crimson+Pro:ital,wght@0,400;0,600;1,400&display=swap');

/* ─── CSS Variables ─── */
:root {
  /* Soft White & Cream Palette */
  --bg-primary: #fefdfb;
  --bg-secondary: #f9f7f4;
  --bg-card: #ffffff;
  --bg-card-hover: #f5f3f0;
  --bg-accent: #fff9f0;
  --bg-overlay: rgba(255, 253, 251, 0.95);

  /* Botanical Greens & Earth Tones */
  --green-sage: #8b9d83;
  --green-mint: #a8c5a5;
  --green-forest: #5a7056;
  --pink-petal: #e8d5d1;
  --pink-rose: #d4a6a0;
  --peach: #f3d4b3;
  --cream: #faf5ef;
  --sand: #e6ddd2;

  /* Soft Chinese Colors */
  --red-soft: #d87d7d;
  --red-coral: #f4a89f;
  --gold-soft: #d4af77;
  --gold-light: #e8c896;
  --jade: #7faa92;
  --lotus-pink: #f2c9c3;

  /* Text Colors */
  --text-primary: #2d3436;
  --text-secondary: #636e72;
  --text-muted: #95a5a6;
  --text-accent: #5a7056;

  /* Gradients */
  --grad-peach: linear-gradient(135deg, #faf5ef, #f3d4b3);
  --grad-mint: linear-gradient(135deg, #e8f5e9, #c8e6c9);
  --grad-rose: linear-gradient(135deg, #fff5f5, #e8d5d1);
  --grad-cream: linear-gradient(135deg, #ffffff, #faf5ef);
  --grad-sage: linear-gradient(135deg, #dce9da, #c8d6c5);

  /* Shadows & Effects */
  --shadow-soft: 0 2px 15px rgba(139, 157, 131, 0.08);
  --shadow-hover: 0 4px 25px rgba(139, 157, 131, 0.12);
  --shadow-card: 0 1px 3px rgba(0, 0, 0, 0.04), 0 1px 2px rgba(0, 0, 0, 0.03);
  --border: rgba(139, 157, 131, 0.12);
  --border-light: rgba(139, 157, 131, 0.06);

  /* Typography */
  --font-main: 'Inter', 'Noto Sans SC', -apple-system, sans-serif;
  --font-heading: 'Crimson Pro', 'Noto Sans SC', serif;
  --font-chinese: 'Noto Sans SC', 'Microsoft YaHei', sans-serif;

  /* Layout */
  --radius: 16px;
  --radius-lg: 24px;
  --radius-xl: 32px;
  --radius-round: 50px;
  --transition: 0.3s cubic-bezier(0.4, 0, 0.2, 1);
  --nav-height: 68px;
}

/* ─── Reset & Base ─── */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  scroll-behavior: smooth;
}

body {
  font-family: var(--font-main);
  background: var(--bg-primary);
  background-image:
    radial-gradient(circle at 20% 30%, rgba(248, 245, 239, 0.5) 0%, transparent 50%),
    radial-gradient(circle at 80% 70%, rgba(232, 245, 233, 0.3) 0%, transparent 50%);
  background-attachment: fixed;
  color: var(--text-primary);
  min-height: 100vh;
  line-height: 1.7;
  overflow-x: hidden;
  position: relative;
}

/* Floral background decoration */
body::before {
  content: '';
  position: fixed;
  top: -50%;
  right: -10%;
  width: 80%;
  height: 80%;
  background: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 400 400'%3E%3Cg opacity='0.03' fill='%238b9d83'%3E%3Cpath d='M200 100c20 0 30 15 30 30s-10 30-30 30-30-15-30-30 10-30 30-30zm-40 20c5-10 15-15 25-10s15 15 10 25-15 15-25 10-15-15-10-25zm80 0c-5-10-15-15-25-10s-15 15-10 25 15 15 25 10 15-15 10-25zm-40 60c10 5 15 15 10 25s-15 15-25 10-15-15-10-25 15-15 25-10z'/%3E%3C/g%3E%3C/svg%3E") no-repeat;
  background-size: contain;
  pointer-events: none;
  z-index: 0;
  animation: floatFloral 60s ease-in-out infinite;
}

body::after {
  content: '';
  position: fixed;
  bottom: -20%;
  left: -10%;
  width: 60%;
  height: 60%;
  background: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 300 300'%3E%3Cg opacity='0.04' fill='%23a8c5a5'%3E%3Ccircle cx='150' cy='80' r='8'/%3E%3Cellipse cx='120' cy='100' rx='12' ry='20' transform='rotate(-30 120 100)'/%3E%3Cellipse cx='180' cy='100' rx='12' ry='20' transform='rotate(30 180 100)'/%3E%3Cpath d='M150 120c-10 0-10 30 0 40 10-10 10-40 0-40z'/%3E%3C/g%3E%3C/svg%3E") no-repeat;
  background-size: contain;
  pointer-events: none;
  z-index: 0;
  animation: floatFloral 80s ease-in-out infinite reverse;
}

@keyframes floatFloral {
  0%, 100% { transform: translate(0, 0) rotate(0deg); }
  33% { transform: translate(20px, -20px) rotate(5deg); }
  66% { transform: translate(-10px, 10px) rotate(-3deg); }
}

/* ─── Scrollbar ─── */
::-webkit-scrollbar { width: 8px; }
::-webkit-scrollbar-track { background: var(--bg-secondary); }
::-webkit-scrollbar-thumb {
  background: var(--green-sage);
  border-radius: 4px;
}
::-webkit-scrollbar-thumb:hover { background: var(--green-forest); }

/* ─── Navigation ─── */
.navbar {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 1000;
  height: var(--nav-height);
  background: var(--bg-overlay);
  backdrop-filter: blur(20px) saturate(120%);
  border-bottom: 1px solid var(--border-light);
  display: flex;
  align-items: center;
  padding: 0 2rem;
  gap: 1.5rem;
  box-shadow: 0 1px 3px rgba(0, 0, 0, 0.02);
}

.nav-brand {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  text-decoration: none;
  font-family: var(--font-heading);
  font-size: 1.4rem;
  font-weight: 600;
  color: var(--text-primary);
  flex-shrink: 0;
  transition: var(--transition);
}

.nav-brand:hover {
  transform: translateY(-1px);
}

.nav-brand .logo-char {
  font-size: 2rem;
  font-family: var(--font-chinese);
  color: var(--green-sage);
  filter: drop-shadow(0 1px 2px rgba(139, 157, 131, 0.3));
}

.nav-brand .brand-text {
  color: var(--green-forest);
  letter-spacing: -0.02em;
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 0.375rem;
  list-style: none;
  flex: 1;
  overflow-x: auto;
  scrollbar-width: none;
  padding: 0.25rem 0;
}
.nav-links::-webkit-scrollbar { display: none; }

.nav-links a {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.5rem 1rem;
  border-radius: var(--radius);
  text-decoration: none;
  color: var(--text-secondary);
  font-size: 0.9rem;
  font-weight: 500;
  white-space: nowrap;
  transition: var(--transition);
  border: 1px solid transparent;
}

.nav-links a:hover {
  background: var(--bg-accent);
  color: var(--text-accent);
  border-color: var(--border-light);
  transform: translateY(-1px);
}

.nav-links a.active {
  background: var(--grad-sage);
  color: var(--green-forest);
  border-color: var(--green-mint);
  font-weight: 600;
  box-shadow: var(--shadow-soft);
}

/* ─── Main Content ─── */
.main-content {
  padding-top: var(--nav-height);
  min-height: 100vh;
  position: relative;
  z-index: 1;
}

/* ─── Buttons ─── */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  padding: 0.75rem 1.75rem;
  border-radius: var(--radius-round);
  border: 2px solid transparent;
  cursor: pointer;
  font-family: var(--font-main);
  font-size: 0.95rem;
  font-weight: 600;
  transition: var(--transition);
  text-decoration: none;
  white-space: nowrap;
  letter-spacing: 0.01em;
}

.btn-primary {
  background: var(--grad-sage);
  color: var(--green-forest);
  border-color: var(--green-mint);
  box-shadow: var(--shadow-soft);
}
.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-hover);
  border-color: var(--green-sage);
}

.btn-soft {
  background: var(--grad-peach);
  color: var(--text-primary);
  border-color: var(--peach);
  box-shadow: var(--shadow-soft);
}
.btn-soft:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-hover);
  border-color: var(--gold-soft);
}

.btn-rose {
  background: var(--grad-rose);
  color: var(--red-soft);
  border-color: var(--pink-rose);
  box-shadow: var(--shadow-soft);
}
.btn-rose:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-hover);
}

.btn-ghost {
  background: transparent;
  color: var(--text-secondary);
  border: 2px solid var(--border);
}
.btn-ghost:hover {
  background: var(--bg-accent);
  border-color: var(--green-mint);
  color: var(--text-primary);
}

.btn-sm { padding: 0.5rem 1.25rem; font-size: 0.875rem; }
.btn-lg { padding: 1rem 2.25rem; font-size: 1.05rem; border-radius: var(--radius-lg); }
.btn-block { width: 100%; }

.btn-icon {
  background: none;
  border: none;
  cursor: pointer;
  color: var(--text-secondary);
  padding: 0.5rem;
  border-radius: var(--radius);
  transition: var(--transition);
  font-size: 1.1rem;
}
.btn-icon:hover {
  color: var(--text-primary);
  background: var(--bg-accent);
}

/* ─── Cards ─── */
.card {
  background: var(--bg-card);
  border: 1px solid var(--border-light);
  border-radius: var(--radius-lg);
  padding: 2rem;
  transition: var(--transition);
  box-shadow: var(--shadow-card);
  position: relative;
  overflow: hidden;
}

.card::before {
  content: '';
  position: absolute;
  top: -50%;
  right: -50%;
  width: 100%;
  height: 100%;
  background: radial-gradient(circle, rgba(168, 197, 165, 0.05) 0%, transparent 70%);
  pointer-events: none;
  transition: var(--transition);
}

.card:hover {
  border-color: var(--green-mint);
  box-shadow: var(--shadow-hover);
  transform: translateY(-2px);
}

.card:hover::before {
  transform: translate(-20%, -20%);
}

.card-glass {
  background: rgba(255, 255, 255, 0.6);
  backdrop-filter: blur(10px);
  border: 1px solid rgba(139, 157, 131, 0.15);
}

.card-accent {
  background: var(--grad-peach);
  border-color: var(--peach);
}

/* ─── Page Header ─── */
.page-header {
  padding: 3rem 2rem 2rem;
  text-align: center;
  position: relative;
}

.page-header h1 {
  font-family: var(--font-heading);
  font-size: 2.5rem;
  font-weight: 600;
  color: var(--green-forest);
  margin-bottom: 0.75rem;
  letter-spacing: -0.02em;
}

.page-header p {
  color: var(--text-secondary);
  font-size: 1.05rem;
  max-width: 600px;
  margin: 0 auto;
}

/* ─── Container ─── */
.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 2rem;
}
.container-sm {
  max-width: 800px;
  margin: 0 auto;
  padding: 0 2rem;
}
.section {
  padding: 3rem 0;
}

/* ─── HSK Level Badges ─── */
.hsk-badge {
  display: inline-flex;
  align-items: center;
  padding: 0.375rem 1rem;
  border-radius: var(--radius-round);
  font-size: 0.8rem;
  font-weight: 700;
  letter-spacing: 0.05em;
  border: 2px solid;
  text-transform: uppercase;
}
.hsk-1 { background: rgba(168, 197, 165, 0.15); color: #5a7056; border-color: #a8c5a5; }
.hsk-2 { background: rgba(139, 157, 131, 0.15); color: #5a7056; border-color: #8b9d83; }
.hsk-3 { background: rgba(243, 212, 179, 0.2); color: #a67c52; border-color: #d4af77; }
.hsk-4 { background: rgba(232, 200, 150, 0.2); color: #9d7e3a; border-color: #d4af77; }
.hsk-5 { background: rgba(244, 168, 159, 0.2); color: #b85b4f; border-color: #f4a89f; }
.hsk-6 { background: rgba(216, 125, 125, 0.2); color: #a04a4a; border-color: #d87d7d; }

/* ─── Hanzi Display ─── */
.hanzi-display {
  font-family: var(--font-chinese);
  font-size: 3.5rem;
  font-weight: 600;
  color: var(--green-forest);
  line-height: 1.2;
  text-shadow: 0 2px 4px rgba(139, 157, 131, 0.1);
}
.hanzi-lg { font-size: 5rem; }
.hanzi-xl { font-size: 8rem; }

.pinyin-text {
  font-size: 1.15rem;
  color: var(--red-soft);
  font-style: italic;
  letter-spacing: 0.05em;
  font-weight: 500;
}

/* ─── Progress Bar ─── */
.progress-bar {
  height: 8px;
  background: var(--bg-secondary);
  border-radius: 4px;
  overflow: hidden;
  box-shadow: inset 0 1px 2px rgba(0, 0, 0, 0.05);
}
.progress-fill {
  height: 100%;
  border-radius: 4px;
  background: var(--grad-sage);
  transition: width 0.6s ease;
  box-shadow: 0 0 8px rgba(139, 157, 131, 0.3);
}
.progress-fill-peach { background: var(--grad-peach); }
.progress-fill-rose { background: var(--grad-rose); }

/* ─── Input & Select ─── */
.input {
  width: 100%;
  padding: 0.875rem 1.25rem;
  background: var(--bg-card);
  border: 2px solid var(--border);
  border-radius: var(--radius);
  color: var(--text-primary);
  font-family: var(--font-main);
  font-size: 0.95rem;
  transition: var(--transition);
  box-shadow: var(--shadow-card);
}
.input:focus {
  outline: none;
  border-color: var(--green-sage);
  box-shadow: 0 0 0 4px rgba(139, 157, 131, 0.1);
  background: white;
}
.input::placeholder {
  color: var(--text-muted);
}

select.input {
  cursor: pointer;
}

/* ─── Tabs ─── */
.tabs {
  display: flex;
  gap: 0.5rem;
  background: var(--bg-secondary);
  padding: 0.5rem;
  border-radius: var(--radius-lg);
  width: fit-content;
  box-shadow: var(--shadow-card);
}
.tab-btn {
  padding: 0.625rem 1.5rem;
  border: none;
  border-radius: var(--radius);
  background: none;
  cursor: pointer;
  color: var(--text-secondary);
  font-family: var(--font-main);
  font-size: 0.9rem;
  font-weight: 500;
  transition: var(--transition);
}
.tab-btn.active {
  background: var(--bg-card);
  color: var(--green-forest);
  font-weight: 600;
  box-shadow: var(--shadow-soft);
}
.tab-btn:hover:not(.active) {
  color: var(--text-primary);
}

/* ─── Score Display ─── */
.score-circle {
  width: 110px;
  height: 110px;
  border-radius: 50%;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  font-weight: 700;
  border: 4px solid;
  background: white;
  box-shadow: var(--shadow-soft);
}
.score-excellent {
  border-color: var(--jade);
  color: var(--jade);
  background: linear-gradient(135deg, #fff, #e8f5e9);
}
.score-good {
  border-color: var(--green-sage);
  color: var(--green-sage);
  background: linear-gradient(135deg, #fff, #f1f8f4);
}
.score-ok {
  border-color: var(--gold-soft);
  color: var(--gold-soft);
  background: linear-gradient(135deg, #fff, #fef9f0);
}
.score-poor {
  border-color: var(--red-soft);
  color: var(--red-soft);
  background: linear-gradient(135deg, #fff, #fff5f5);
}

/* ─── Alert / Notification ─── */
.alert {
  padding: 1rem 1.5rem;
  border-radius: var(--radius);
  border-left: 4px solid;
  font-size: 0.95rem;
  margin: 1.25rem 0;
  box-shadow: var(--shadow-card);
}
.alert-info {
  background: linear-gradient(135deg, #e3f2fd, #f8fbff);
  border-color: #90caf9;
  color: #1976d2;
}
.alert-success {
  background: var(--grad-mint);
  border-color: var(--jade);
  color: var(--green-forest);
}
.alert-warning {
  background: var(--grad-peach);
  border-color: var(--gold-soft);
  color: #8b6914;
}
.alert-error {
  background: var(--grad-rose);
  border-color: var(--red-soft);
  color: #b71c1c;
}

/* ─── Grid Layouts ─── */
.grid-2 {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 1.5rem;
}
.grid-3 {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1.5rem;
}
.grid-4 {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 1.25rem;
}
.grid-auto {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(240px, 1fr));
  gap: 1.5rem;
}

@media (max-width: 768px) {
  .grid-2, .grid-3, .grid-4 { grid-template-columns: 1fr; }
  .nav-links { gap: 0.25rem; }
  .nav-links a { font-size: 0.85rem; padding: 0.45rem 0.8rem; }
  .hanzi-xl { font-size: 5rem; }
  .page-header h1 { font-size: 2rem; }
  .container, .container-sm { padding: 0 1.25rem; }
}

/* ─── Animations ─── */
@keyframes fadeIn {
  from { opacity: 0; transform: translateY(12px); }
  to { opacity: 1; transform: none; }
}
@keyframes pulse {
  0%, 100% { opacity: 1; }
  50% { opacity: 0.6; }
}
@keyframes spin {
  to { transform: rotate(360deg); }
}
@keyframes slideUp {
  from { transform: translateY(20px); opacity: 0; }
  to { transform: none; opacity: 1; }
}
@keyframes glow {
  0%, 100% { box-shadow: 0 0 10px rgba(139, 157, 131, 0.3); }
  50% { box-shadow: 0 0 20px rgba(139, 157, 131, 0.6); }
}
@keyframes float {
  0%, 100% { transform: translateY(0); }
  50% { transform: translateY(-10px); }
}

.animate-fade { animation: fadeIn 0.5s ease; }
.animate-pulse { animation: pulse 2.5s infinite; }
.animate-spin { animation: spin 1s linear infinite; }
.animate-float { animation: float 4s ease-in-out infinite; }

/* ─── Loading Spinner ─── */
.spinner {
  width: 36px;
  height: 36px;
  border: 3px solid var(--border);
  border-top-color: var(--green-sage);
  border-radius: 50%;
  animation: spin 0.8s linear infinite;
}

/* ─── Waveform / Audio Visual ─── */
.waveform {
  display: flex;
  align-items: center;
  gap: 4px;
  height: 48px;
}
.waveform-bar {
  width: 5px;
  border-radius: 3px;
  background: var(--green-sage);
  transition: height 0.1s ease;
}

/* ─── Tone Colors ─── */
.tone-1 { color: var(--red-soft); }
.tone-2 { color: var(--gold-soft); }
.tone-3 { color: var(--jade); }
.tone-4 { color: var(--green-sage); }
.tone-5 { color: var(--text-secondary); }

/* ─── Chat Bubble ─── */
.chat-bubble {
  max-width: 85%;
  padding: 1rem 1.25rem;
  border-radius: var(--radius-lg);
  font-size: 0.95rem;
  line-height: 1.7;
  margin-bottom: 0.75rem;
  box-shadow: var(--shadow-card);
}
.chat-user {
  background: var(--grad-sage);
  color: var(--green-forest);
  margin-left: auto;
  border-bottom-right-radius: 6px;
}
.chat-ai {
  background: var(--bg-card);
  border: 1px solid var(--border-light);
  border-bottom-left-radius: 6px;
  color: var(--text-primary);
}
.chat-ai strong {
  color: var(--green-forest);
}

/* ─── Tooltip ─── */
[data-tooltip] {
  position: relative;
  cursor: help;
}
[data-tooltip]:hover::after {
  content: attr(data-tooltip);
  position: absolute;
  bottom: calc(100% + 10px);
  left: 50%;
  transform: translateX(-50%);
  background: var(--green-forest);
  color: white;
  padding: 0.5rem 0.875rem;
  border-radius: var(--radius);
  font-size: 0.825rem;
  white-space: nowrap;
  z-index: 100;
  pointer-events: none;
  box-shadow: var(--shadow-hover);
}

/* ─── Footer ─── */
.footer {
  text-align: center;
  padding: 3rem 2rem;
  color: var(--text-muted);
  font-size: 0.9rem;
  border-top: 1px solid var(--border-light);
  margin-top: 5rem;
  background: var(--bg-secondary);
}

.footer strong {
  color: var(--green-forest);
}

/* ─── Decorative Floral Elements ─── */
.floral-accent {
  position: absolute;
  opacity: 0.05;
  pointer-events: none;
  color: var(--green-sage);
  font-size: 4rem;
  z-index: 0;
}

/* ─── Soft Divider ─── */
.divider {
  height: 1px;
  background: linear-gradient(to right, transparent, var(--border), transparent);
  margin: 2rem 0;
}

/* ─── Badge ─── */
.badge {
  display: inline-flex;
  align-items: center;
  padding: 0.25rem 0.75rem;
  border-radius: var(--radius-round);
  font-size: 0.75rem;
  font-weight: 600;
  background: var(--bg-accent);
  color: var(--text-accent);
  border: 1px solid var(--border-light);
}