/* ===================================
   NexBrief — Global CSS Design System
   Dark Premium Theme
=================================== */

/* Google Fonts */
@import url('https://fonts.googleapis.com/css2?family=Inter:wght@300;400;500;600;700;800;900&display=swap');

/* ---- CSS Custom Properties ---- */
:root {
  /* Colors */
  --color-bg: #0f172a;
  --color-bg-2: #0b1120;
  --color-surface: #1e293b;
  --color-surface-2: #162032;
  --color-border: #1e293b;
  --color-border-2: #334155;

  --color-primary: #6366f1;
  --color-primary-dark: #4f46e5;
  --color-primary-light: #818cf8;
  --color-accent: #8b5cf6;
  --color-success: #10b981;
  --color-danger: #ef4444;
  --color-warning: #f59e0b;
  --color-info: #3b82f6;

  --color-text: #f1f5f9;
  --color-text-2: #cbd5e1;
  --color-text-muted: #94a3b8;
  --color-text-faint: #64748b;

  /* Typography */
  --font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;

  /* Spacing */
  --radius-sm: 8px;
  --radius-md: 12px;
  --radius-lg: 16px;
  --radius-xl: 24px;

  /* Shadows */
  --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.4);
  --shadow-md: 0 4px 16px rgba(0, 0, 0, 0.4);
  --shadow-lg: 0 8px 32px rgba(0, 0, 0, 0.5);
  --shadow-glow: 0 0 40px rgba(99, 102, 241, 0.2);

  /* Transitions */
  --transition: 0.25s cubic-bezier(0.4, 0, 0.2, 1);
  --transition-fast: 0.15s ease;
}

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

html { scroll-behavior: smooth; }

body {
  background-color: var(--color-bg);
  color: var(--color-text);
  font-family: var(--font-family);
  font-size: 16px;
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  overflow-x: hidden;
}

a { color: var(--color-primary-light); text-decoration: none; transition: color var(--transition-fast); }
a:hover { color: var(--color-primary); }

img { max-width: 100%; display: block; }

/* ---- Utility ---- */
.container { max-width: 1100px; margin: 0 auto; padding: 0 24px; }
.hidden { display: none !important; }
.gradient-text {
  background: linear-gradient(135deg, #818cf8, #c084fc, #f472b6);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

/* ---- Navbar ---- */
.navbar {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 900;
  background: rgba(15, 23, 42, 0.85);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border-bottom: 1px solid rgba(255, 255, 255, 0.06);
  transition: var(--transition);
}
.navbar.scrolled {
  background: rgba(11, 17, 32, 0.95);
  box-shadow: var(--shadow-md);
}
.nav-container {
  max-width: 1100px;
  margin: 0 auto;
  padding: 0 24px;
  height: 68px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}
.nav-logo {
  font-size: 22px;
  font-weight: 900;
  color: var(--color-text);
  letter-spacing: -0.5px;
  text-decoration: none;
}
.logo-nex { color: var(--color-primary-light); }
.nav-actions { display: flex; align-items: center; gap: 12px; }

/* ---- Buttons ---- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 10px 22px;
  border-radius: var(--radius-md);
  font-family: var(--font-family);
  font-size: 14px;
  font-weight: 600;
  cursor: pointer;
  border: none;
  outline: none;
  transition: all var(--transition);
  text-decoration: none;
  white-space: nowrap;
}
.btn:disabled { opacity: 0.6; cursor: not-allowed; }

.btn-primary {
  background: linear-gradient(135deg, var(--color-primary), var(--color-accent));
  color: #fff;
  box-shadow: 0 4px 16px rgba(99, 102, 241, 0.35);
}
.btn-primary:hover:not(:disabled) {
  transform: translateY(-2px);
  box-shadow: 0 8px 24px rgba(99, 102, 241, 0.45);
}
.btn-primary:active { transform: translateY(0); }

.btn-ghost {
  background: transparent;
  color: var(--color-text-2);
  border: 1px solid var(--color-border-2);
}
.btn-ghost:hover { background: var(--color-surface); color: var(--color-text); }

.btn-danger {
  background: linear-gradient(135deg, #ef4444, #dc2626);
  color: #fff;
}
.btn-danger:hover { transform: translateY(-1px); box-shadow: 0 4px 12px rgba(239,68,68,0.4); }

.btn-success {
  background: linear-gradient(135deg, #10b981, #059669);
  color: #fff;
}
.btn-success:hover { transform: translateY(-1px); }

.btn-sm { padding: 7px 14px; font-size: 13px; border-radius: var(--radius-sm); }
.btn-lg { padding: 14px 32px; font-size: 16px; border-radius: var(--radius-lg); }
.btn-full { width: 100%; }
.link-btn {
  background: none;
  border: none;
  color: var(--color-primary-light);
  font-weight: 600;
  cursor: pointer;
  font-family: var(--font-family);
  font-size: inherit;
  padding: 0;
  transition: color var(--transition-fast);
}
.link-btn:hover { color: var(--color-primary); }

/* Spinner inside button */
.btn-spinner {
  width: 16px;
  height: 16px;
  border: 2px solid rgba(255,255,255,0.3);
  border-top-color: #fff;
  border-radius: 50%;
  animation: spin 0.7s linear infinite;
  display: inline-block;
}
@keyframes spin { to { transform: rotate(360deg); } }

/* ---- Hero Section ---- */
.hero {
  position: relative;
  min-height: 100vh;
  display: flex;
  align-items: center;
  padding: 100px 0 80px;
  overflow: hidden;
}
.hero-bg {
  position: absolute;
  inset: 0;
  pointer-events: none;
}
.hero-orb {
  position: absolute;
  border-radius: 50%;
  filter: blur(80px);
  opacity: 0.2;
}
.orb-1 { width: 600px; height: 600px; background: #6366f1; top: -200px; left: -200px; animation: float 8s ease-in-out infinite; }
.orb-2 { width: 400px; height: 400px; background: #8b5cf6; bottom: -100px; right: -100px; animation: float 10s ease-in-out infinite reverse; }
.orb-3 { width: 300px; height: 300px; background: #3b82f6; top: 50%; left: 50%; transform: translate(-50%, -50%); animation: float 6s ease-in-out infinite 2s; }

@keyframes float {
  0%, 100% { transform: translate(0, 0); }
  50% { transform: translate(20px, -20px); }
}
.orb-3 { animation: float3 6s ease-in-out infinite 2s; }
@keyframes float3 {
  0%, 100% { transform: translate(-50%, -50%); }
  50% { transform: translate(calc(-50% + 20px), calc(-50% - 20px)); }
}

.hero .container { position: relative; z-index: 1; text-align: center; }

.hero-badge {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  background: rgba(99, 102, 241, 0.12);
  border: 1px solid rgba(99, 102, 241, 0.3);
  color: var(--color-primary-light);
  font-size: 13px;
  font-weight: 600;
  padding: 8px 20px;
  border-radius: 100px;
  margin-bottom: 32px;
  letter-spacing: 0.3px;
  animation: fadeInDown 0.6s ease both;
}
.badge-dot {
  width: 8px;
  height: 8px;
  background: #10b981;
  border-radius: 50%;
  animation: pulse-dot 2s ease infinite;
}
@keyframes pulse-dot {
  0%, 100% { opacity: 1; transform: scale(1); }
  50% { opacity: 0.5; transform: scale(1.3); }
}

.hero-title {
  font-size: clamp(40px, 7vw, 80px);
  font-weight: 900;
  line-height: 1.1;
  letter-spacing: -2px;
  margin-bottom: 24px;
  animation: fadeInUp 0.6s ease 0.1s both;
}
.hero-subtitle {
  font-size: clamp(16px, 2.5vw, 20px);
  color: var(--color-text-muted);
  max-width: 600px;
  margin: 0 auto 40px;
  line-height: 1.7;
  animation: fadeInUp 0.6s ease 0.2s both;
}
.hero-subtitle strong { color: var(--color-text-2); }

.hero-cta {
  display: flex;
  gap: 16px;
  justify-content: center;
  flex-wrap: wrap;
  margin-bottom: 56px;
  animation: fadeInUp 0.6s ease 0.3s both;
}

.hero-stats {
  display: inline-flex;
  align-items: center;
  gap: 32px;
  background: rgba(30, 41, 59, 0.6);
  backdrop-filter: blur(10px);
  border: 1px solid var(--color-border-2);
  border-radius: var(--radius-xl);
  padding: 20px 40px;
  animation: fadeInUp 0.6s ease 0.4s both;
}
.stat-item { text-align: center; }
.stat-number { display: block; font-size: 22px; font-weight: 800; color: var(--color-text); }
.stat-label { font-size: 12px; color: var(--color-text-faint); text-transform: uppercase; letter-spacing: 0.5px; }
.stat-divider { width: 1px; height: 40px; background: var(--color-border-2); }

/* ---- Features Section ---- */
.features {
  padding: 100px 0;
  background: linear-gradient(180deg, var(--color-bg) 0%, var(--color-bg-2) 50%, var(--color-bg) 100%);
}
.section-header { text-align: center; margin-bottom: 60px; }
.section-badge {
  display: inline-block;
  background: rgba(99,102,241,0.1);
  color: var(--color-primary-light);
  font-size: 13px;
  font-weight: 700;
  padding: 6px 16px;
  border-radius: 100px;
  border: 1px solid rgba(99,102,241,0.2);
  text-transform: uppercase;
  letter-spacing: 1px;
  margin-bottom: 16px;
}
.section-title {
  font-size: clamp(28px, 4vw, 42px);
  font-weight: 800;
  letter-spacing: -1px;
  margin-bottom: 12px;
}
.section-subtitle { color: var(--color-text-muted); font-size: 16px; }

.features-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 24px;
}
.feature-card {
  background: var(--color-surface-2);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: 32px;
  transition: all var(--transition);
  position: relative;
  overflow: hidden;
}
.feature-card::before {
  content: '';
  position: absolute;
  inset: 0;
  background: linear-gradient(135deg, rgba(99,102,241,0.05) 0%, transparent 60%);
  opacity: 0;
  transition: opacity var(--transition);
}
.feature-card:hover { border-color: rgba(99,102,241,0.3); transform: translateY(-4px); box-shadow: var(--shadow-glow); }
.feature-card:hover::before { opacity: 1; }
.feature-icon {
  width: 52px;
  height: 52px;
  border-radius: var(--radius-md);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 24px;
  margin-bottom: 20px;
}
.feature-card h3 { font-size: 18px; font-weight: 700; margin-bottom: 10px; }
.feature-card p { color: var(--color-text-muted); font-size: 14px; line-height: 1.6; }

/* ---- Modal ---- */
.modal-overlay {
  position: fixed;
  inset: 0;
  background: rgba(0, 0, 0, 0.7);
  backdrop-filter: blur(8px);
  z-index: 1000;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 20px;
  opacity: 0;
  pointer-events: none;
  transition: opacity var(--transition);
}
.modal-overlay.active {
  opacity: 1;
  pointer-events: all;
}

.modal {
  background: var(--color-surface);
  border: 1px solid var(--color-border-2);
  border-radius: var(--radius-xl);
  width: 100%;
  max-width: 460px;
  padding: 32px;
  position: relative;
  transform: translateY(20px) scale(0.97);
  transition: transform var(--transition);
  box-shadow: 0 24px 64px rgba(0, 0, 0, 0.6);
}
.modal-overlay.active .modal {
  transform: translateY(0) scale(1);
}

.modal-close {
  position: absolute;
  top: 16px;
  right: 16px;
  width: 32px;
  height: 32px;
  background: var(--color-surface-2);
  border: 1px solid var(--color-border-2);
  border-radius: var(--radius-sm);
  color: var(--color-text-muted);
  font-size: 18px;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: all var(--transition-fast);
}
.modal-close:hover { color: var(--color-text); background: var(--color-border-2); }

.modal-tabs {
  display: flex;
  gap: 4px;
  background: var(--color-bg);
  border-radius: var(--radius-md);
  padding: 4px;
  margin-bottom: 28px;
}
.modal-tab {
  flex: 1;
  padding: 10px;
  background: transparent;
  border: none;
  border-radius: var(--radius-sm);
  color: var(--color-text-muted);
  font-family: var(--font-family);
  font-size: 14px;
  font-weight: 600;
  cursor: pointer;
  transition: all var(--transition-fast);
}
.modal-tab.active {
  background: var(--color-surface);
  color: var(--color-text);
  box-shadow: var(--shadow-sm);
}

.modal-header { text-align: center; margin-bottom: 28px; }
.modal-logo { font-size: 20px; font-weight: 900; margin-bottom: 12px; }
.modal-title { font-size: 22px; font-weight: 800; margin-bottom: 6px; }
.modal-subtitle { color: var(--color-text-muted); font-size: 14px; }

/* ---- Forms ---- */
.form-group { margin-bottom: 20px; }
.form-label {
  display: block;
  font-size: 13px;
  font-weight: 600;
  color: var(--color-text-2);
  margin-bottom: 8px;
}
.form-input {
  width: 100%;
  padding: 12px 16px;
  background: var(--color-bg);
  border: 1.5px solid var(--color-border-2);
  border-radius: var(--radius-md);
  color: var(--color-text);
  font-family: var(--font-family);
  font-size: 15px;
  outline: none;
  transition: border-color var(--transition-fast), box-shadow var(--transition-fast);
}
.form-input::placeholder { color: var(--color-text-faint); }
.form-input:focus {
  border-color: var(--color-primary);
  box-shadow: 0 0 0 3px rgba(99, 102, 241, 0.15);
}
.form-input.error { border-color: var(--color-danger); }

.input-wrapper { position: relative; }
.input-wrapper .form-input { padding-right: 48px; }
.toggle-pw {
  position: absolute;
  right: 14px;
  top: 50%;
  transform: translateY(-50%);
  background: none;
  border: none;
  cursor: pointer;
  font-size: 16px;
  opacity: 0.5;
  transition: opacity var(--transition-fast);
}
.toggle-pw:hover { opacity: 1; }

.field-error { display: block; color: var(--color-danger); font-size: 12px; margin-top: 5px; min-height: 16px; }
.server-error {
  color: var(--color-danger);
  font-size: 13px;
  padding: 10px 14px;
  background: rgba(239, 68, 68, 0.1);
  border: 1px solid rgba(239, 68, 68, 0.2);
  border-radius: var(--radius-sm);
  margin-bottom: 16px;
  display: none;
}
.server-error.visible { display: block; }

.modal-switch { text-align: center; color: var(--color-text-muted); font-size: 14px; margin-top: 20px; }

/* ── Forgot Password ── */
.forgot-link-row {
  display: flex;
  justify-content: flex-end;
  margin: -8px 0 16px;
}
.forgot-link-btn { font-size: 13px; color: var(--color-primary-light); }
.forgot-step-badge {
  display: inline-block;
  background: rgba(99,102,241,0.12);
  border: 1px solid rgba(99,102,241,0.25);
  color: var(--color-primary-light);
  font-size: 11px;
  font-weight: 700;
  padding: 4px 12px;
  border-radius: 100px;
  letter-spacing: 0.5px;
  margin-bottom: 10px;
}
.forgot-step-badge.success-step {
  background: rgba(16,185,129,0.1);
  border-color: rgba(16,185,129,0.25);
  color: #6ee7b7;
}

/* ── OTP Input Boxes ── */
.otp-inputs {
  display: flex;
  gap: 10px;
  justify-content: center;
  margin: 4px 0 6px;
}
.otp-box {
  width: 50px;
  height: 56px;
  background: var(--color-bg);
  border: 2px solid var(--color-border-2);
  border-radius: var(--radius-md);
  color: var(--color-text);
  font-family: 'Inter', monospace;
  font-size: 24px;
  font-weight: 800;
  text-align: center;
  outline: none;
  transition: all var(--transition-fast);
  caret-color: var(--color-primary-light);
}
.otp-box:focus {
  border-color: var(--color-primary);
  box-shadow: 0 0 0 3px rgba(99, 102, 241, 0.18);
  transform: scale(1.05);
}
.otp-box.filled {
  border-color: var(--color-primary);
  color: var(--color-primary-light);
}
.otp-box.error-box {
  border-color: var(--color-danger);
  animation: shake 0.3s ease;
}
@keyframes shake {
  0%, 100% { transform: translateX(0); }
  25% { transform: translateX(-5px); }
  75% { transform: translateX(5px); }
}

/* OTP Timer */
.otp-timer-row {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 16px;
  flex-wrap: wrap;
  gap: 8px;
}
.otp-timer { font-size: 12px; color: var(--color-text-faint); }
.otp-timer strong { color: var(--color-warning); }

@media (max-width: 480px) {
  .otp-box { width: 40px; height: 48px; font-size: 20px; }
  .otp-inputs { gap: 7px; }
}

/* ---- Toast ---- */
.toast {
  position: fixed;
  bottom: 32px;
  left: 50%;
  transform: translateX(-50%) translateY(100px);
  background: var(--color-surface);
  border: 1px solid var(--color-border-2);
  border-radius: var(--radius-md);
  padding: 14px 24px;
  font-size: 14px;
  font-weight: 600;
  z-index: 2000;
  box-shadow: var(--shadow-lg);
  transition: transform 0.35s cubic-bezier(0.34, 1.56, 0.64, 1), opacity 0.3s ease;
  opacity: 0;
  white-space: nowrap;
  max-width: 90vw;
}
.toast.show { transform: translateX(-50%) translateY(0); opacity: 1; }
.toast.success { border-color: rgba(16, 185, 129, 0.4); color: #6ee7b7; }
.toast.error { border-color: rgba(239, 68, 68, 0.4); color: #fca5a5; }
.toast.info { border-color: rgba(99, 102, 241, 0.4); color: var(--color-primary-light); }

/* ---- Footer ---- */
.footer {
  background: var(--color-bg-2);
  border-top: 1px solid var(--color-border);
  padding: 48px 0 24px;
  margin-top: 80px;
}
.footer-top {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: 40px;
  flex-wrap: wrap;
  margin-bottom: 40px;
}
.footer-logo { font-size: 22px; font-weight: 900; margin-bottom: 10px; }
.footer-brand p { color: var(--color-text-muted); font-size: 14px; max-width: 280px; }
.footer-links { display: flex; flex-direction: column; gap: 12px; }
.footer-links a, .footer-link-btn {
  color: var(--color-text-muted);
  font-size: 14px;
  transition: color var(--transition-fast);
  text-align: left;
}
.footer-links a:hover, .footer-link-btn:hover { color: var(--color-primary-light); }
.footer-bottom { border-top: 1px solid var(--color-border); padding-top: 20px; text-align: center; color: var(--color-text-faint); font-size: 13px; }

/* ---- Animations ---- */
@keyframes fadeInDown {
  from { opacity: 0; transform: translateY(-16px); }
  to { opacity: 1; transform: translateY(0); }
}
@keyframes fadeInUp {
  from { opacity: 0; transform: translateY(16px); }
  to { opacity: 1; transform: translateY(0); }
}

/* ---- Responsive ---- */
@media (max-width: 768px) {
  .nav-actions .btn-ghost { display: none; }
  .hero-stats { gap: 20px; padding: 16px 24px; flex-wrap: wrap; }
  .hero-cta { flex-direction: column; align-items: center; }
  .btn-lg { width: 100%; max-width: 360px; }
  .modal { padding: 24px; }
  .footer-top { flex-direction: column; }
}
@media (max-width: 480px) {
  .hero-stats { display: none; }
}