/* ============================================================
   Training Hub — Design Tokens & Base
   Extracted from brucevu.com design system for training independence.
   This file replaces the full base.css (portfolio CSS) with ONLY
   the shared foundations that training.css depends on.
   ============================================================ */

/* ---------- CSS Custom Properties ---------- */
:root {
  /* Primary */
  --color-near-black: #141413;
  --color-terracotta: #c96442;
  --color-coral: #d97757;

  /* Secondary */
  --color-error: #b53333;
  --color-focus: #3898ec;

  /* Surfaces */
  --color-parchment: #f5f4ed;
  --color-ivory: #faf9f5;
  --color-white: #ffffff;
  --color-warm-sand: #e8e6dc;
  --color-dark-surface: #30302e;
  --color-cream-light: #faf9f5;

  /* Neutrals */
  --color-charcoal-warm: #4d4c48;
  --color-olive-gray: #5e5d59;
  --color-stone-gray: #87867f;
  --color-mocha-brown: #6b5b4e;
  --color-text-secondary: #87867f;

  /* Borders */
  --color-border-cream: #f0eee6;
  --color-border-warm: #e8e6dc;
  --color-border-dark: #30302e;

  /* Rings */
  --color-ring-warm: #d1cfc5;
  --color-ring-subtle: #dedcd1;

  /* Accent */
  --color-muted-charcoal: #6b6b67;
  --color-burnt-sienna: #a34e2e;
  --color-text-secondary: #6b6b67;

  /* Typography */
  --font-serif: 'Georgia', 'Times New Roman', serif;
  --font-heading: 'Georgia', 'Times New Roman', serif;
  --font-sans: 'Inter', system-ui, -apple-system, sans-serif;
  --font-mono: 'JetBrains Mono', 'Fira Code', monospace;

  /* Spacing */
  --space-xs: 4px;
  --space-sm: 8px;
  --space-md: 16px;
  --space-lg: 24px;
  --space-xl: 32px;
  --space-2xl: 48px;
  --space-3xl: 64px;
  --space-4xl: 80px;
  --space-5xl: 120px;

  /* Border Radius */
  --radius-sm: 6px;
  --radius-md: 8px;
  --radius-lg: 12px;
  --radius-xl: 16px;
  --radius-2xl: 24px;
  --radius-full: 32px;

  /* Shadows */
  --shadow-ring: 0px 0px 0px 1px;
  --shadow-whisper: 0px 4px 24px rgba(0, 0, 0, 0.05);

  /* Transition */
  --transition-base: 0.3s cubic-bezier(0.4, 0, 0.2, 1);
  --transition-slow: 0.6s cubic-bezier(0.4, 0, 0.2, 1);
}

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

html {
  scroll-behavior: smooth;
  scroll-padding-top: 80px;
  font-size: 16px;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  scrollbar-width: thin;
  scrollbar-color: #d1cfc5 var(--color-parchment);
}

body {
  font-family: var(--font-sans);
  font-size: 1rem;
  font-weight: 400;
  line-height: 1.60;
  color: var(--color-near-black);
  background-color: var(--color-parchment);
  overflow-x: hidden;
  word-break: break-word;
  overflow-wrap: break-word;
}

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

a {
  color: inherit;
  text-decoration: none;
  transition: color var(--transition-base);
}

ul, ol {
  list-style: none;
}

button {
  font-family: inherit;
  cursor: pointer;
  border: none;
  background: none;
}

/* ---------- Buttons ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-sm);
  padding: 12px 24px;
  border-radius: var(--radius-md);
  font-family: var(--font-sans);
  font-size: 1rem;
  font-weight: 500;
  transition: all var(--transition-base);
  cursor: pointer;
  border: none;
  text-decoration: none;
  white-space: nowrap;
}

.btn--primary {
  background-color: var(--color-terracotta);
  color: var(--color-ivory);
  box-shadow: var(--shadow-ring) var(--color-terracotta);
}

.btn--primary:hover {
  background-color: var(--color-coral);
  transform: translateY(-2px);
  box-shadow: 0px 4px 16px rgba(201, 100, 66, 0.3);
}

.btn--secondary {
  background-color: var(--color-warm-sand);
  color: var(--color-charcoal-warm);
  box-shadow: var(--shadow-ring) var(--color-ring-warm);
}

.btn--secondary:hover {
  background-color: var(--color-ring-warm);
  transform: translateY(-2px);
}

.btn--sm {
  padding: 8px 16px;
  font-size: 0.88rem;
}

.btn--full {
  width: 100%;
}

.btn--google {
  background-color: var(--color-white);
  color: var(--color-charcoal-warm);
  border: 1px solid var(--color-border-cream);
  gap: var(--space-sm);
}

.btn--google:hover {
  background-color: var(--color-ivory);
  border-color: var(--color-ring-warm);
}

.btn--completed {
  background-color: rgba(34, 197, 94, 0.1);
  color: #166534;
  cursor: default;
}

.btn--saved {
  background-color: rgba(34, 197, 94, 0.1);
  color: #166534;
}

.btn--outline {
  background-color: transparent;
  color: var(--color-olive-gray);
  border: 1px solid var(--color-border-cream);
}

.btn--outline:hover {
  background-color: var(--color-ivory);
  color: var(--color-near-black);
  border-color: var(--color-ring-warm);
}

/* ---------- Container ---------- */
.container {
  width: 100%;
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 var(--space-lg);
  box-sizing: border-box;
  overflow-x: hidden;
}

/* ---------- Section Base ---------- */
.section__header {
  text-align: center;
  margin-bottom: var(--space-3xl);
}

.section__overline {
  color: var(--color-terracotta);
  margin-bottom: var(--space-md);
  display: block;
}

.section__title {
  margin-bottom: var(--space-md);
}

.section__subtitle {
  font-family: var(--font-sans);
  font-size: 1.125rem;
  color: var(--color-olive-gray);
  max-width: 600px;
  margin: 0 auto;
}

/* ---------- Typography Utilities ---------- */
.overline {
  font-size: 0.75rem;
  font-weight: 500;
  line-height: 1.60;
  letter-spacing: 2px;
  text-transform: uppercase;
}

.heading-section {
  font-family: var(--font-serif);
  font-size: 2.5rem;
  line-height: 1.20;
  font-weight: 500;
  color: var(--color-near-black);
}

/* ---------- Form Controls ---------- */
.form-group {
  display: flex;
  flex-direction: column;
  gap: var(--space-xs);
}

.form-group label {
  font-size: 0.88rem;
  font-weight: 500;
  color: var(--color-charcoal-warm);
}

.form-input {
  width: 100%;
  padding: var(--space-sm) var(--space-md);
  font-family: var(--font-sans);
  font-size: 0.94rem;
  color: var(--color-near-black);
  background: var(--color-ivory);
  border: 1px solid var(--color-border-cream);
  border-radius: var(--radius-lg);
  outline: none;
  transition: border-color var(--transition-base), box-shadow var(--transition-base);
}

.form-input::placeholder {
  color: var(--color-stone-gray);
}

.form-input:focus {
  border-color: var(--color-terracotta);
  box-shadow: 0 0 0 3px rgba(201, 100, 66, 0.12);
}

/* ---------- Footer ---------- */
.footer {
  background: var(--color-near-black);
  padding: var(--space-lg) 0;
}

.footer__inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: var(--space-md);
}

.footer__copy {
  font-size: 0.82rem;
  color: var(--color-stone-gray);
}

/* ---------- Back to Top ---------- */
.back-to-top {
  position: fixed;
  bottom: var(--space-xl);
  right: var(--space-xl);
  width: 40px;
  height: 40px;
  border-radius: 50%;
  background: var(--color-terracotta);
  color: var(--color-white);
  font-size: 1.1rem;
  display: flex;
  align-items: center;
  justify-content: center;
  opacity: 0;
  visibility: hidden;
  transition: all var(--transition-base);
  z-index: 900;
  border: none;
  cursor: pointer;
}

.back-to-top--visible {
  opacity: 1;
  visibility: visible;
}

.back-to-top:hover {
  background: var(--color-coral);
  transform: translateY(-3px);
}

/* ---------- Responsive Utilities ---------- */
@media (max-width: 767px) {
  .heading-section { font-size: 1.8rem; }
  .section__header { margin-bottom: var(--space-xl); }
  .container { padding: 0 var(--space-md); }
}

@media (max-width: 479px) {
  .heading-section { font-size: 1.5rem; }
}

/* ---------- Custom Scrollbar (synced from brucevu.com) ---------- */
::-webkit-scrollbar { width: 8px; }
::-webkit-scrollbar-track { background: var(--color-parchment); }
::-webkit-scrollbar-thumb { background: #d1cfc5; border-radius: 4px; }
::-webkit-scrollbar-thumb:hover { background: #b0aea5; }

/* ---------- Text Selection ---------- */
::selection { background-color: rgba(201, 100, 66, 0.2); color: var(--color-near-black); }