/* ===================================================
   chatp – AI Chat Interface | Stylesheet
   =================================================== */

/* ---------- CSS Custom Properties ---------- */
:root {
  /* Colors */
  --clr-bg: #0a0e1a;
  --clr-bg-alt: #0f172a;
  --clr-surface: #1e293b;
  --clr-surface-hover: #273548;
  --clr-border: rgba(148, 163, 184, 0.1);
  --clr-border-hover: rgba(148, 163, 184, 0.2);
  --clr-text: #e2e8f0;
  --clr-text-muted: #94a3b8;
  --clr-text-dim: #64748b;
  --clr-primary: #06b6d4;
  --clr-primary-hover: #22d3ee;
  --clr-primary-glow: rgba(6, 182, 212, 0.25);
  --clr-accent: #a855f7;
  --clr-accent-glow: rgba(168, 85, 247, 0.25);
  --clr-success: #10b981;
  --clr-warning: #f59e0b;
  --clr-danger: #ef4444;
  --clr-white: #ffffff;

  /* Typography */
  --ff-body: 'Inter', system-ui, -apple-system, sans-serif;
  --fs-xs: 0.75rem;
  --fs-sm: 0.875rem;
  --fs-base: 1rem;
  --fs-lg: 1.125rem;
  --fs-xl: 1.25rem;
  --fs-2xl: 1.5rem;
  --fs-3xl: 1.875rem;
  --fs-4xl: 2.25rem;
  --fs-5xl: 3rem;
  --fs-6xl: 3.75rem;

  /* Spacing */
  --sp-1: 0.25rem;
  --sp-2: 0.5rem;
  --sp-3: 0.75rem;
  --sp-4: 1rem;
  --sp-5: 1.25rem;
  --sp-6: 1.5rem;
  --sp-8: 2rem;
  --sp-10: 2.5rem;
  --sp-12: 3rem;
  --sp-16: 4rem;
  --sp-20: 5rem;
  --sp-24: 6rem;

  /* Layout */
  --max-width: 1200px;
  --header-h: 70px;
  --sidebar-w: 280px;
  --radius-sm: 0.5rem;
  --radius-md: 0.75rem;
  --radius-lg: 1rem;
  --radius-xl: 1.5rem;
  --radius-full: 9999px;

  /* Transitions */
  --ease: cubic-bezier(0.4, 0, 0.2, 1);
  --duration: 0.3s;

  /* Shadows */
  --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.3);
  --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.3), 0 2px 4px -2px rgba(0, 0, 0, 0.3);
  --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.3), 0 4px 6px -4px rgba(0, 0, 0, 0.3);
  --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.3), 0 8px 10px -6px rgba(0, 0, 0, 0.3);
}

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

html {
  scroll-behavior: smooth;
  -webkit-text-size-adjust: 100%;
  scroll-padding-top: var(--header-h);
}

body {
  font-family: var(--ff-body);
  font-size: var(--fs-base);
  line-height: 1.6;
  color: var(--clr-text);
  background: var(--clr-bg);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  overflow-x: hidden;
}

img, svg { display: block; max-width: 100%; }
a { color: inherit; text-decoration: none; }
ul, ol { list-style: none; }
button, input, textarea { font: inherit; border: none; outline: none; background: none; color: inherit; }
button { cursor: pointer; }
textarea { resize: none; }

/* ---------- Utility ---------- */
.container {
  width: 100%;
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 var(--sp-6);
}

.glass {
  background: rgba(30, 41, 59, 0.6);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  border: 1px solid var(--clr-border);
}

.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0,0,0,0);
  white-space: nowrap;
  border: 0;
}

/* ---------- Buttons ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--sp-2);
  padding: var(--sp-3) var(--sp-6);
  border-radius: var(--radius-md);
  font-weight: 500;
  font-size: var(--fs-sm);
  transition: all var(--duration) var(--ease);
  white-space: nowrap;
  line-height: 1.4;
}

.btn--primary {
  background: linear-gradient(135deg, var(--clr-primary), var(--clr-accent));
  color: var(--clr-white);
  box-shadow: 0 0 20px var(--clr-primary-glow), 0 0 20px var(--clr-accent-glow);
}
.btn--primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 0 30px var(--clr-primary-glow), 0 0 30px var(--clr-accent-glow);
}
.btn--primary:active { transform: translateY(0); }

.btn--ghost {
  color: var(--clr-text);
  border: 1px solid var(--clr-border-hover);
  background: rgba(255,255,255,0.03);
}
.btn--ghost:hover {
  border-color: var(--clr-primary);
  color: var(--clr-primary);
  background: rgba(6, 182, 212, 0.05);
  transform: translateY(-2px);
}
.btn--ghost:active { transform: translateY(0); }

.btn--lg { padding: var(--sp-4) var(--sp-8); font-size: var(--fs-base); }
.btn--full { width: 100%; }

/* ---------- Section Helpers ---------- */
.section-header {
  text-align: center;
  max-width: 640px;
  margin: 0 auto var(--sp-16);
}
.section-badge {
  display: inline-block;
  padding: var(--sp-1) var(--sp-4);
  border-radius: var(--radius-full);
  font-size: var(--fs-xs);
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: var(--clr-primary);
  border: 1px solid rgba(6, 182, 212, 0.3);
  background: rgba(6, 182, 212, 0.08);
  margin-bottom: var(--sp-4);
}
.section-title {
  font-size: clamp(var(--fs-3xl), 4vw, var(--fs-4xl));
  font-weight: 700;
  line-height: 1.2;
  margin-bottom: var(--sp-4);
}
.section-desc {
  font-size: var(--fs-lg);
  color: var(--clr-text-muted);
}

/* ==========================================================
   HEADER / NAV
   ========================================================== */
.header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  height: var(--header-h);
  z-index: 1000;
  background: rgba(10, 14, 26, 0.8);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid transparent;
  transition: border-color var(--duration) var(--ease), box-shadow var(--duration) var(--ease);
}
.header--scrolled {
  border-bottom-color: var(--clr-border);
  box-shadow: var(--shadow-lg);
}
.nav {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 100%;
}
.nav__logo {
  display: flex;
  align-items: center;
  gap: var(--sp-3);
  font-size: var(--fs-xl);
  font-weight: 700;
  color: var(--clr-white);
  z-index: 1001;
}
.nav__logo span {
  background: linear-gradient(135deg, var(--clr-primary), var(--clr-accent));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}
.nav__menu {
  display: flex;
  align-items: center;
  gap: var(--sp-8);
}
.nav__list {
  display: flex;
  align-items: center;
  gap: var(--sp-1);
}
.nav__link {
  padding: var(--sp-2) var(--sp-3);
  border-radius: var(--radius-sm);
  font-size: var(--fs-sm);
  color: var(--clr-text-muted);
  transition: color var(--duration) var(--ease), background var(--duration) var(--ease);
}
.nav__link:hover {
  color: var(--clr-white);
  background: rgba(255,255,255,0.05);
}
.nav__buttons {
  display: flex;
  align-items: center;
  gap: var(--sp-3);
}

/* Hamburger */
.nav__toggle {
  display: none;
  flex-direction: column;
  gap: 5px;
  width: 28px;
  z-index: 1001;
}
.nav__toggle span {
  display: block;
  width: 100%;
  height: 2px;
  background: var(--clr-text);
  border-radius: 2px;
  transition: all var(--duration) var(--ease);
}
.nav__toggle.active span:nth-child(1) { transform: translateY(7px) rotate(45deg); }
.nav__toggle.active span:nth-child(2) { opacity: 0; }
.nav__toggle.active span:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }

/* ==========================================================
   HERO
   ========================================================== */
.hero {
  position: relative;
  min-height: 100vh;
  display: flex;
  align-items: center;
  padding: calc(var(--header-h) + var(--sp-12)) 0 var(--sp-16);
  overflow: hidden;
}
.hero__bg {
  position: absolute;
  inset: 0;
  pointer-events: none;
  z-index: 0;
}
.hero__orb {
  position: absolute;
  border-radius: 50%;
  filter: blur(100px);
  opacity: 0.35;
  animation: orbFloat 12s ease-in-out infinite;
}
.hero__orb--1 {
  width: 500px;
  height: 500px;
  background: var(--clr-primary);
  top: -10%;
  right: -5%;
}
.hero__orb--2 {
  width: 400px;
  height: 400px;
  background: var(--clr-accent);
  bottom: -10%;
  left: -5%;
  animation-delay: -4s;
}
.hero__orb--3 {
  width: 300px;
  height: 300px;
  background: #3b82f6;
  top: 50%;
  left: 40%;
  animation-delay: -8s;
}
@keyframes orbFloat {
  0%, 100% { transform: translate(0, 0) scale(1); }
  33% { transform: translate(30px, -30px) scale(1.05); }
  66% { transform: translate(-20px, 20px) scale(0.95); }
}

.hero__grid {
  position: relative;
  z-index: 1;
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--sp-16);
  align-items: center;
}
.hero__content { max-width: 560px; }
.hero__title {
  font-size: clamp(var(--fs-4xl), 5vw, var(--fs-6xl));
  font-weight: 800;
  line-height: 1.1;
  margin-bottom: var(--sp-6);
  background: linear-gradient(135deg, var(--clr-white) 0%, var(--clr-text-muted) 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}
.hero__text {
  font-size: var(--fs-lg);
  color: var(--clr-text-muted);
  margin-bottom: var(--sp-8);
  line-height: 1.7;
}
.hero__cta {
  display: flex;
  gap: var(--sp-4);
  flex-wrap: wrap;
  margin-bottom: var(--sp-12);
}
.hero__stats {
  display: flex;
  gap: var(--sp-10);
}
.hero__stat {
  display: flex;
  flex-direction: column;
}
.hero__stat-num {
  font-size: var(--fs-2xl);
  font-weight: 700;
  color: var(--clr-white);
}
.hero__stat-label {
  font-size: var(--fs-xs);
  color: var(--clr-text-dim);
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

/* Hero Chat Card */
.hero__preview {
  display: flex;
  justify-content: center;
}
.chat-card {
  width: 100%;
  max-width: 420px;
  border-radius: var(--radius-xl);
  overflow: hidden;
  box-shadow: var(--shadow-xl), 0 0 60px var(--clr-primary-glow);
  animation: cardFloat 6s ease-in-out infinite;
}
@keyframes cardFloat {
  0%, 100% { transform: translateY(0); }
  50% { transform: translateY(-12px); }
}
.chat-card__header {
  display: flex;
  align-items: center;
  gap: var(--sp-2);
  padding: var(--sp-4) var(--sp-5);
  border-bottom: 1px solid var(--clr-border);
}
.chat-card__dot {
  width: 10px;
  height: 10px;
  border-radius: 50%;
}
.chat-card__dot--red { background: var(--clr-danger); }
.chat-card__dot--yellow { background: var(--clr-warning); }
.chat-card__dot--green { background: var(--clr-success); }
.chat-card__title {
  margin-left: auto;
  font-size: var(--fs-sm);
  font-weight: 600;
  color: var(--clr-text-muted);
}
.chat-card__body {
  padding: var(--sp-5);
  display: flex;
  flex-direction: column;
  gap: var(--sp-4);
  min-height: 220px;
}
.chat-card__msg {
  display: flex;
  gap: var(--sp-3);
  max-width: 90%;
}
.chat-card__msg--user {
  align-self: flex-end;
  flex-direction: row-reverse;
}
.chat-card__avatar {
  width: 30px;
  height: 30px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
}
.chat-card__avatar--ai {
  background: linear-gradient(135deg, var(--clr-primary), var(--clr-accent));
  color: var(--clr-white);
}
.chat-card__bubble {
  padding: var(--sp-3) var(--sp-4);
  border-radius: var(--radius-lg);
  font-size: var(--fs-sm);
  line-height: 1.5;
}
.chat-card__msg--ai .chat-card__bubble {
  background: var(--clr-surface);
  border-bottom-left-radius: var(--sp-1);
}
.chat-card__msg--user .chat-card__bubble {
  background: linear-gradient(135deg, var(--clr-primary), var(--clr-accent));
  color: var(--clr-white);
  border-bottom-right-radius: var(--sp-1);
}
.chat-card__input {
  display: flex;
  align-items: center;
  gap: var(--sp-3);
  padding: var(--sp-4) var(--sp-5);
  border-top: 1px solid var(--clr-border);
}
.chat-card__input input {
  flex: 1;
  padding: var(--sp-3) var(--sp-4);
  background: var(--clr-bg);
  border: 1px solid var(--clr-border);
  border-radius: var(--radius-md);
  font-size: var(--fs-sm);
  color: var(--clr-text-muted);
}
.chat-card__send {
  width: 36px;
  height: 36px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  background: linear-gradient(135deg, var(--clr-primary), var(--clr-accent));
  color: var(--clr-white);
}

/* Typing Dots */
.typing-dots span {
  animation: typingBlink 1.4s infinite;
  font-weight: 700;
  font-size: var(--fs-lg);
}
.typing-dots span:nth-child(2) { animation-delay: 0.2s; }
.typing-dots span:nth-child(3) { animation-delay: 0.4s; }
@keyframes typingBlink {
  0%, 60%, 100% { opacity: 0.2; }
  30% { opacity: 1; }
}

/* ==========================================================
   CHAT INTERFACE SECTION
   ========================================================== */
.chat-section {
  padding: var(--sp-4) 0;
  min-height: 85vh;
}
.chat-layout {
  display: flex;
  height: 80vh;
  max-width: 1400px;
  margin: 0 auto;
  border-radius: var(--radius-xl);
  overflow: hidden;
  border: 1px solid var(--clr-border);
  background: var(--clr-bg-alt);
  box-shadow: var(--shadow-xl);
  position: relative;
}

/* Sidebar */
.sidebar {
  width: var(--sidebar-w);
  min-width: var(--sidebar-w);
  background: var(--clr-bg);
  border-right: 1px solid var(--clr-border);
  display: flex;
  flex-direction: column;
  transition: transform var(--duration) var(--ease);
}
.sidebar__header {
  padding: var(--sp-4);
}
.sidebar__new-chat {
  width: 100%;
  padding: var(--sp-3) var(--sp-4);
  font-size: var(--fs-sm);
  border-radius: var(--radius-md);
}
.sidebar__search {
  display: flex;
  align-items: center;
  gap: var(--sp-2);
  margin: 0 var(--sp-4) var(--sp-4);
  padding: var(--sp-2) var(--sp-3);
  border: 1px solid var(--clr-border);
  border-radius: var(--radius-md);
  color: var(--clr-text-dim);
}
.sidebar__search input {
  flex: 1;
  font-size: var(--fs-sm);
}
.sidebar__search input::placeholder { color: var(--clr-text-dim); }
.sidebar__history {
  flex: 1;
  overflow-y: auto;
  padding: 0 var(--sp-3);
}
.sidebar__label {
  font-size: var(--fs-xs);
  color: var(--clr-text-dim);
  text-transform: uppercase;
  letter-spacing: 0.08em;
  padding: var(--sp-3) var(--sp-2);
  font-weight: 600;
}
.sidebar__list { margin-bottom: var(--sp-2); }
.sidebar__item {
  display: flex;
  align-items: center;
  gap: var(--sp-3);
  padding: var(--sp-3) var(--sp-3);
  border-radius: var(--radius-md);
  font-size: var(--fs-sm);
  color: var(--clr-text-muted);
  cursor: pointer;
  transition: all var(--duration) var(--ease);
}
.sidebar__item:hover {
  background: var(--clr-surface);
  color: var(--clr-text);
}
.sidebar__item--active {
  background: var(--clr-surface);
  color: var(--clr-white);
}
.sidebar__item span {
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}
.sidebar__profile {
  display: flex;
  align-items: center;
  gap: var(--sp-3);
  padding: var(--sp-4);
  border-top: 1px solid var(--clr-border);
}
.sidebar__avatar {
  width: 34px;
  height: 34px;
  border-radius: 50%;
  background: linear-gradient(135deg, var(--clr-primary), var(--clr-accent));
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: var(--fs-sm);
  font-weight: 600;
  color: var(--clr-white);
  flex-shrink: 0;
}
.sidebar__user-info {
  flex: 1;
  min-width: 0;
}
.sidebar__username {
  display: block;
  font-size: var(--fs-sm);
  font-weight: 500;
  color: var(--clr-text);
}
.sidebar__plan {
  display: block;
  font-size: var(--fs-xs);
  color: var(--clr-text-dim);
}
.sidebar__settings {
  color: var(--clr-text-dim);
  padding: var(--sp-2);
  border-radius: var(--radius-sm);
  transition: color var(--duration) var(--ease), background var(--duration) var(--ease);
}
.sidebar__settings:hover {
  color: var(--clr-text);
  background: var(--clr-surface);
}

.sidebar-toggle {
  display: none;
  position: absolute;
  top: var(--sp-3);
  left: var(--sp-3);
  z-index: 5;
  width: 36px;
  height: 36px;
  border-radius: var(--radius-sm);
  align-items: center;
  justify-content: center;
  color: var(--clr-text-muted);
  background: var(--clr-surface);
  border: 1px solid var(--clr-border);
  transition: color var(--duration) var(--ease);
}
.sidebar-toggle:hover { color: var(--clr-white); }

/* Chat Main */
.chat-main {
  flex: 1;
  display: flex;
  flex-direction: column;
  min-width: 0;
}
.chat-main__header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: var(--sp-4) var(--sp-6);
  border-bottom: 1px solid var(--clr-border);
}
.chat-main__title {
  font-size: var(--fs-base);
  font-weight: 600;
}
.chat-main__actions {
  display: flex;
  gap: var(--sp-2);
}
.chat-main__action {
  width: 34px;
  height: 34px;
  border-radius: var(--radius-sm);
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--clr-text-dim);
  transition: all var(--duration) var(--ease);
}
.chat-main__action:hover {
  background: var(--clr-surface);
  color: var(--clr-text);
}

/* Messages */
.chat-main__messages {
  flex: 1;
  overflow-y: auto;
  padding: var(--sp-6);
  display: flex;
  flex-direction: column;
  gap: var(--sp-6);
  scroll-behavior: smooth;
}
.message {
  display: flex;
  gap: var(--sp-4);
  max-width: 800px;
  width: 100%;
  animation: msgSlideIn 0.3s var(--ease);
}
@keyframes msgSlideIn {
  from { opacity: 0; transform: translateY(12px); }
  to { opacity: 1; transform: translateY(0); }
}
.message--ai { margin-right: auto; }
.message--user { margin-left: auto; }
.message__avatar {
  width: 36px;
  height: 36px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
}
.message__avatar--ai {
  background: linear-gradient(135deg, var(--clr-primary), var(--clr-accent));
  color: var(--clr-white);
}
.message__avatar--user {
  background: var(--clr-surface);
  color: var(--clr-text);
  font-weight: 600;
  font-size: var(--fs-sm);
}
.message__content {
  flex: 1;
  min-width: 0;
}
.message__name {
  font-size: var(--fs-sm);
  font-weight: 600;
  margin-bottom: var(--sp-1);
  color: var(--clr-text);
}
.message__text {
  font-size: var(--fs-sm);
  line-height: 1.7;
  color: var(--clr-text-muted);
}
.message__text p { margin-bottom: var(--sp-3); }
.message__text p:last-child { margin-bottom: 0; }
.message__text ul, .message__text ol {
  padding-left: var(--sp-6);
  margin-bottom: var(--sp-3);
}
.message__text li {
  list-style: disc;
  margin-bottom: var(--sp-1);
}
.message__text ol li { list-style: decimal; }
.message__text strong { color: var(--clr-text); }
.message__time {
  font-size: var(--fs-xs);
  color: var(--clr-text-dim);
  margin-top: var(--sp-2);
}
.message__actions {
  display: flex;
  gap: var(--sp-2);
  margin-top: var(--sp-3);
}
.message__action-btn {
  display: inline-flex;
  align-items: center;
  gap: var(--sp-1);
  padding: var(--sp-1) var(--sp-3);
  border-radius: var(--radius-sm);
  font-size: var(--fs-xs);
  color: var(--clr-text-dim);
  border: 1px solid var(--clr-border);
  transition: all var(--duration) var(--ease);
}
.message__action-btn:hover {
  border-color: var(--clr-primary);
  color: var(--clr-primary);
  background: rgba(6, 182, 212, 0.05);
}

/* Chat Input */
.chat-main__input-area {
  padding: var(--sp-4) var(--sp-6) var(--sp-4);
}
.chat-input {
  display: flex;
  align-items: flex-end;
  gap: var(--sp-3);
  padding: var(--sp-3) var(--sp-4);
  background: var(--clr-surface);
  border: 1px solid var(--clr-border);
  border-radius: var(--radius-lg);
  transition: border-color var(--duration) var(--ease), box-shadow var(--duration) var(--ease);
}
.chat-input:focus-within {
  border-color: var(--clr-primary);
  box-shadow: 0 0 0 3px var(--clr-primary-glow);
}
.chat-input__attach {
  width: 36px;
  height: 36px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--clr-text-dim);
  flex-shrink: 0;
  transition: color var(--duration) var(--ease);
}
.chat-input__attach:hover { color: var(--clr-text); }
.chat-input__field {
  flex: 1;
  padding: var(--sp-2) 0;
  font-size: var(--fs-sm);
  line-height: 1.5;
  max-height: 150px;
  overflow-y: auto;
  color: var(--clr-text);
}
.chat-input__field::placeholder { color: var(--clr-text-dim); }
.chat-input__send {
  width: 36px;
  height: 36px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  background: linear-gradient(135deg, var(--clr-primary), var(--clr-accent));
  color: var(--clr-white);
  flex-shrink: 0;
  transition: transform var(--duration) var(--ease), box-shadow var(--duration) var(--ease);
}
.chat-input__send:hover {
  transform: scale(1.05);
  box-shadow: 0 0 20px var(--clr-primary-glow);
}
.chat-input__disclaimer {
  text-align: center;
  font-size: var(--fs-xs);
  color: var(--clr-text-dim);
  margin-top: var(--sp-2);
}

/* ==========================================================
   FEATURES
   ========================================================== */
.features {
  padding: var(--sp-24) 0;
  position: relative;
}
.features__grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--sp-6);
}
.feature-card {
  padding: var(--sp-8);
  border-radius: var(--radius-xl);
  transition: all var(--duration) var(--ease);
}
.feature-card:hover {
  transform: translateY(-4px);
  border-color: var(--clr-border-hover);
  box-shadow: var(--shadow-lg), 0 0 40px rgba(6, 182, 212, 0.06);
}
.feature-card__icon {
  width: 52px;
  height: 52px;
  border-radius: var(--radius-md);
  display: flex;
  align-items: center;
  justify-content: center;
  background: linear-gradient(135deg, rgba(6, 182, 212, 0.15), rgba(168, 85, 247, 0.15));
  color: var(--clr-primary);
  margin-bottom: var(--sp-5);
}
.feature-card__title {
  font-size: var(--fs-lg);
  font-weight: 600;
  margin-bottom: var(--sp-3);
  color: var(--clr-white);
}
.feature-card__desc {
  font-size: var(--fs-sm);
  color: var(--clr-text-muted);
  line-height: 1.7;
}

/* ==========================================================
   WHY CHATP
   ========================================================== */
.why-chatp {
  padding: var(--sp-24) 0;
}
.why-chatp__grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--sp-16);
  align-items: center;
}
.why-chatp__content {
  display: flex;
  flex-direction: column;
  gap: var(--sp-6);
}
.why-chatp__item {
  display: flex;
  gap: var(--sp-5);
  padding: var(--sp-6);
  border-radius: var(--radius-lg);
  border: 1px solid var(--clr-border);
  background: rgba(30, 41, 59, 0.3);
  transition: all var(--duration) var(--ease);
}
.why-chatp__item:hover {
  border-color: var(--clr-border-hover);
  background: rgba(30, 41, 59, 0.6);
  transform: translateX(4px);
}
.why-chatp__num {
  font-size: var(--fs-3xl);
  font-weight: 800;
  background: linear-gradient(135deg, var(--clr-primary), var(--clr-accent));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  flex-shrink: 0;
  line-height: 1;
}
.why-chatp__item h3 {
  font-size: var(--fs-base);
  font-weight: 600;
  margin-bottom: var(--sp-2);
  color: var(--clr-white);
}
.why-chatp__item p {
  font-size: var(--fs-sm);
  color: var(--clr-text-muted);
  line-height: 1.7;
}
.why-chatp__visual {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  padding: var(--sp-16);
  border-radius: var(--radius-xl);
  text-align: center;
  min-height: 400px;
}
.why-chatp__circle {
  width: 140px;
  height: 140px;
  border-radius: 50%;
  background: linear-gradient(135deg, rgba(6, 182, 212, 0.1), rgba(168, 85, 247, 0.1));
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--clr-primary);
  margin-bottom: var(--sp-6);
  animation: pulse 3s ease-in-out infinite;
}
@keyframes pulse {
  0%, 100% { box-shadow: 0 0 0 0 rgba(6, 182, 212, 0.2); }
  50% { box-shadow: 0 0 0 30px rgba(6, 182, 212, 0); }
}
.why-chatp__visual-text {
  font-size: var(--fs-lg);
  font-weight: 600;
  color: var(--clr-text-muted);
}

/* ==========================================================
   PRICING
   ========================================================== */
.pricing {
  padding: var(--sp-24) 0;
}
.pricing__grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--sp-6);
  align-items: start;
}
.pricing-card {
  border-radius: var(--radius-xl);
  padding: var(--sp-8);
  position: relative;
  transition: all var(--duration) var(--ease);
}
.pricing-card:hover {
  transform: translateY(-4px);
}
.pricing-card--popular {
  border-color: var(--clr-primary);
  background: rgba(6, 182, 212, 0.05);
  box-shadow: 0 0 40px var(--clr-primary-glow);
}
.pricing-card__badge {
  position: absolute;
  top: -12px;
  left: 50%;
  transform: translateX(-50%);
  padding: var(--sp-1) var(--sp-5);
  background: linear-gradient(135deg, var(--clr-primary), var(--clr-accent));
  color: var(--clr-white);
  font-size: var(--fs-xs);
  font-weight: 600;
  border-radius: var(--radius-full);
  white-space: nowrap;
}
.pricing-card__header { margin-bottom: var(--sp-8); }
.pricing-card__name {
  font-size: var(--fs-xl);
  font-weight: 600;
  margin-bottom: var(--sp-2);
  color: var(--clr-white);
}
.pricing-card__price {
  font-size: var(--fs-5xl);
  font-weight: 800;
  color: var(--clr-white);
}
.pricing-card__price span {
  font-size: var(--fs-base);
  font-weight: 400;
  color: var(--clr-text-dim);
}
.pricing-card__features {
  display: flex;
  flex-direction: column;
  gap: var(--sp-4);
  margin-bottom: var(--sp-8);
}
.pricing-card__features li {
  display: flex;
  align-items: center;
  gap: var(--sp-3);
  font-size: var(--fs-sm);
  color: var(--clr-text-muted);
}
.pricing-card__features svg {
  color: var(--clr-success);
  flex-shrink: 0;
}

/* ==========================================================
   FAQ
   ========================================================== */
.faq {
  padding: var(--sp-24) 0;
}
.faq__list {
  max-width: 720px;
  margin: 0 auto;
  display: flex;
  flex-direction: column;
  gap: var(--sp-4);
}
.faq__item {
  border-radius: var(--radius-lg);
  overflow: hidden;
  transition: border-color var(--duration) var(--ease);
}
.faq__item[open] {
  border-color: var(--clr-primary);
}
.faq__question {
  padding: var(--sp-5) var(--sp-6);
  font-weight: 600;
  font-size: var(--fs-base);
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: space-between;
  color: var(--clr-text);
  transition: color var(--duration) var(--ease);
  list-style: none;
}
.faq__question::-webkit-details-marker { display: none; }
.faq__question::after {
  content: '+';
  font-size: var(--fs-xl);
  color: var(--clr-primary);
  transition: transform var(--duration) var(--ease);
  flex-shrink: 0;
  margin-left: var(--sp-4);
}
.faq__item[open] .faq__question::after {
  transform: rotate(45deg);
}
.faq__question:hover { color: var(--clr-primary); }
.faq__answer {
  padding: 0 var(--sp-6) var(--sp-5);
  font-size: var(--fs-sm);
  color: var(--clr-text-muted);
  line-height: 1.7;
}

/* ==========================================================
   FOOTER
   ========================================================== */
.footer {
  padding: var(--sp-20) 0 var(--sp-8);
  border-top: 1px solid var(--clr-border);
  background: var(--clr-bg);
}
.footer__grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1fr;
  gap: var(--sp-12);
  margin-bottom: var(--sp-12);
}
.footer__logo {
  display: flex;
  align-items: center;
  gap: var(--sp-3);
  font-size: var(--fs-xl);
  font-weight: 700;
  margin-bottom: var(--sp-5);
}
.footer__logo span {
  background: linear-gradient(135deg, var(--clr-primary), var(--clr-accent));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}
.footer__desc {
  font-size: var(--fs-sm);
  color: var(--clr-text-muted);
  line-height: 1.7;
  margin-bottom: var(--sp-6);
}
.footer__social {
  display: flex;
  gap: var(--sp-3);
}
.footer__social-link {
  width: 36px;
  height: 36px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--clr-text-dim);
  border: 1px solid var(--clr-border);
  transition: all var(--duration) var(--ease);
}
.footer__social-link:hover {
  color: var(--clr-primary);
  border-color: var(--clr-primary);
  background: rgba(6, 182, 212, 0.08);
  transform: translateY(-2px);
}
.footer__links h4 {
  font-size: var(--fs-sm);
  font-weight: 600;
  color: var(--clr-white);
  margin-bottom: var(--sp-5);
  text-transform: uppercase;
  letter-spacing: 0.05em;
}
.footer__links li { margin-bottom: var(--sp-3); }
.footer__links a {
  font-size: var(--fs-sm);
  color: var(--clr-text-muted);
  transition: color var(--duration) var(--ease);
}
.footer__links a:hover { color: var(--clr-primary); }
.footer__bottom {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding-top: var(--sp-8);
  border-top: 1px solid var(--clr-border);
  font-size: var(--fs-xs);
  color: var(--clr-text-dim);
}

/* ==========================================================
   SCROLLBAR
   ========================================================== */
::-webkit-scrollbar { width: 6px; }
::-webkit-scrollbar-track { background: transparent; }
::-webkit-scrollbar-thumb {
  background: var(--clr-surface);
  border-radius: 3px;
}
::-webkit-scrollbar-thumb:hover { background: var(--clr-surface-hover); }

/* ==========================================================
   RESPONSIVE — TABLET (768px)
   ========================================================== */
@media (max-width: 1024px) {
  .hero__grid {
    grid-template-columns: 1fr;
    text-align: center;
  }
  .hero__content { max-width: 100%; margin: 0 auto; }
  .hero__cta { justify-content: center; }
  .hero__stats { justify-content: center; }
  .hero__preview { margin-top: var(--sp-8); }

  .features__grid {
    grid-template-columns: repeat(2, 1fr);
  }

  .why-chatp__grid {
    grid-template-columns: 1fr;
  }
  .why-chatp__visual { min-height: 280px; }

  .pricing__grid {
    grid-template-columns: repeat(2, 1fr);
  }
  .pricing__grid > :last-child {
    grid-column: span 2;
    max-width: 400px;
    justify-self: center;
  }

  .footer__grid {
    grid-template-columns: 1fr 1fr;
  }
}

@media (max-width: 768px) {
  :root {
    --header-h: 60px;
    --sidebar-w: 260px;
  }

  /* Nav Mobile */
  .nav__toggle {
    display: flex;
  }
  .nav__menu {
    position: fixed;
    top: 0;
    right: 0;
    width: min(320px, 85vw);
    height: 100vh;
    background: var(--clr-bg);
    border-left: 1px solid var(--clr-border);
    flex-direction: column;
    padding: calc(var(--header-h) + var(--sp-8)) var(--sp-6) var(--sp-8);
    transform: translateX(100%);
    transition: transform var(--duration) var(--ease);
    z-index: 999;
  }
  .nav__menu.active { transform: translateX(0); }
  .nav__list {
    flex-direction: column;
    align-items: stretch;
    gap: 0;
    width: 100%;
  }
  .nav__link {
    display: block;
    padding: var(--sp-4) var(--sp-3);
    font-size: var(--fs-base);
    border-bottom: 1px solid var(--clr-border);
  }
  .nav__buttons {
    flex-direction: column;
    width: 100%;
    margin-top: var(--sp-6);
  }
  .nav__buttons .btn { width: 100%; }

  /* Overlay */
  .nav-overlay {
    position: fixed;
    inset: 0;
    background: rgba(0,0,0,0.6);
    z-index: 998;
    opacity: 0;
    visibility: hidden;
    transition: all var(--duration) var(--ease);
  }
  .nav-overlay.active {
    opacity: 1;
    visibility: visible;
  }

  /* Hero */
  .hero { min-height: auto; padding-bottom: var(--sp-12); }
  .hero__stats { gap: var(--sp-6); }
  .chat-card { max-width: 340px; }

  /* Chat Section */
  .sidebar {
    position: absolute;
    left: 0;
    top: 0;
    bottom: 0;
    z-index: 10;
    transform: translateX(-100%);
  }
  .sidebar.active { transform: translateX(0); }
  .sidebar-toggle { display: flex; }

  .chat-main__header {
    padding-left: calc(var(--sp-6) + 44px);
  }

  /* Features */
  .features__grid { grid-template-columns: 1fr; }

  /* Pricing */
  .pricing__grid {
    grid-template-columns: 1fr;
  }
  .pricing__grid > :last-child {
    grid-column: auto;
    max-width: none;
  }

  /* Footer */
  .footer__grid {
    grid-template-columns: 1fr;
    gap: var(--sp-8);
  }
  .footer__bottom {
    flex-direction: column;
    gap: var(--sp-2);
    text-align: center;
  }
}

@media (max-width: 480px) {
  .container { padding: 0 var(--sp-4); }
  .hero__title { font-size: var(--fs-3xl); }
  .hero__stats {
    flex-direction: column;
    gap: var(--sp-4);
    align-items: center;
  }
  .section-title { font-size: var(--fs-2xl); }
  .chat-layout { height: 75vh; border-radius: var(--radius-lg); }
  .chat-main__messages { padding: var(--sp-4); }
  .chat-main__input-area { padding: var(--sp-3) var(--sp-4); }
  .message { gap: var(--sp-3); }
  .message__avatar { width: 30px; height: 30px; }
}

/* ==========================================================
   SEO CONTENT SECTION
   ========================================================== */
.content-section {
  padding: var(--sp-20) 0 var(--sp-24);
  position: relative;
  border-top: 1px solid var(--clr-border);
}
.content-section::before {
  content: '';
  position: absolute;
  top: 0;
  left: 50%;
  transform: translateX(-50%);
  width: 600px;
  height: 600px;
  background: radial-gradient(circle, rgba(6, 182, 212, 0.04) 0%, transparent 70%);
  pointer-events: none;
}
.content-section__inner {
  position: relative;
  z-index: 1;
}

/* Article long-form content */
.seo-content {
  max-width: 800px;
  margin: 0 auto;
}
.seo-content h2 {
  font-size: clamp(var(--fs-xl), 2.5vw, var(--fs-2xl));
  font-weight: 700;
  color: var(--clr-white);
  margin-top: var(--sp-12);
  margin-bottom: var(--sp-5);
  padding-bottom: var(--sp-3);
  border-bottom: 1px solid var(--clr-border);
  line-height: 1.3;
}
.seo-content h2:first-child {
  margin-top: 0;
}
.seo-content h3 {
  font-size: var(--fs-lg);
  font-weight: 600;
  color: var(--clr-text);
  margin-top: var(--sp-8);
  margin-bottom: var(--sp-3);
  line-height: 1.4;
}
.seo-content p {
  font-size: var(--fs-base);
  color: var(--clr-text-muted);
  line-height: 1.85;
  margin-bottom: var(--sp-5);
}
.seo-content strong {
  color: var(--clr-text);
  font-weight: 600;
}
.seo-content a {
  color: var(--clr-primary);
  text-decoration: underline;
  text-decoration-color: rgba(6, 182, 212, 0.3);
  text-underline-offset: 3px;
  transition: text-decoration-color var(--duration) var(--ease);
}
.seo-content a:hover {
  text-decoration-color: var(--clr-primary);
}
.seo-content ul,
.seo-content ol {
  padding-left: var(--sp-6);
  margin-bottom: var(--sp-6);
}
.seo-content ul li {
  list-style: disc;
  font-size: var(--fs-base);
  color: var(--clr-text-muted);
  line-height: 1.85;
  margin-bottom: var(--sp-3);
  padding-left: var(--sp-2);
}
.seo-content ol li {
  list-style: decimal;
  font-size: var(--fs-base);
  color: var(--clr-text-muted);
  line-height: 1.85;
  margin-bottom: var(--sp-4);
  padding-left: var(--sp-2);
}
.seo-content li strong {
  color: var(--clr-text);
}

/* Content CTA */
.content-cta {
  display: flex;
  justify-content: center;
  gap: var(--sp-5);
  flex-wrap: wrap;
  margin-top: var(--sp-12);
  padding-top: var(--sp-10);
  border-top: 1px solid var(--clr-border);
}

@media (max-width: 768px) {
  .seo-content {
    max-width: 100%;
  }
  .seo-content h2 {
    margin-top: var(--sp-10);
    font-size: var(--fs-xl);
  }
  .content-cta {
    flex-direction: column;
    align-items: center;
  }
  .content-cta .btn {
    width: 100%;
    max-width: 320px;
  }
}