/* ========================================================================== */
/* Variables                                                                  */
/* ========================================================================== */

:root {
  /* Colors */
  --color-bg: #f5f5f7;
  --color-surface: #ffffff;
  --color-surface-subtle: #f0f0f2;
  --color-text: #1f2933;
  --color-text-muted: #6b7280;
  --color-border-subtle: #e2e4ea;

  --color-primary: #4b6cb7; /* calm, trustworthy blue */
  --color-primary-soft: #e3e9f7;
  --color-primary-dark: #364986;

  --color-success: #1a936f;
  --color-success-soft: #e0f4ed;
  --color-warning: #d97706;
  --color-warning-soft: #fff4e1;
  --color-danger: #d64545;
  --color-danger-soft: #ffe5e5;

  /* Neutral grays */
  --gray-50: #f9fafb;
  --gray-100: #f3f4f6;
  --gray-200: #e5e7eb;
  --gray-300: #d1d5db;
  --gray-400: #9ca3af;
  --gray-500: #6b7280;
  --gray-600: #4b5563;
  --gray-700: #374151;
  --gray-800: #1f2933;
  --gray-900: #111827;

  /* Typography */
  --font-sans: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto,
    "Helvetica Neue", Arial, "Noto Sans", sans-serif, "Apple Color Emoji",
    "Segoe UI Emoji", "Segoe UI Symbol", "Noto Color Emoji";
  --font-heading: "SF Pro Display", system-ui, -apple-system, BlinkMacSystemFont,
    "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;

  --font-size-xs: 0.75rem;   /* 12px */
  --font-size-sm: 0.875rem;  /* 14px */
  --font-size-base: 1rem;    /* 16px */
  --font-size-lg: 1.125rem;  /* 18px */
  --font-size-xl: 1.25rem;   /* 20px */
  --font-size-2xl: 1.5rem;   /* 24px */
  --font-size-3xl: 1.875rem; /* 30px */
  --font-size-4xl: 2.25rem;  /* 36px */

  --line-height-tight: 1.2;
  --line-height-snug: 1.35;
  --line-height-normal: 1.5;
  --line-height-relaxed: 1.7;

  /* Spacing scale (0–96px) */
  --space-0: 0;
  --space-1: 0.25rem;  /* 4px */
  --space-2: 0.5rem;   /* 8px */
  --space-3: 0.75rem;  /* 12px */
  --space-4: 1rem;     /* 16px */
  --space-5: 1.25rem;  /* 20px */
  --space-6: 1.5rem;   /* 24px */
  --space-7: 1.75rem;  /* 28px */
  --space-8: 2rem;     /* 32px */
  --space-10: 2.5rem;  /* 40px */
  --space-12: 3rem;    /* 48px */
  --space-16: 4rem;    /* 64px */
  --space-20: 5rem;    /* 80px */
  --space-24: 6rem;    /* 96px */

  /* Radius */
  --radius-none: 0;
  --radius-sm: 0.25rem;  /* 4px */
  --radius-md: 0.5rem;   /* 8px */
  --radius-lg: 0.75rem;  /* 12px */
  --radius-xl: 1rem;     /* 16px */
  --radius-full: 9999px;

  /* Shadows */
  --shadow-sm: 0 1px 2px rgba(15, 23, 42, 0.06);
  --shadow-md: 0 8px 20px rgba(15, 23, 42, 0.08);
  --shadow-lg: 0 18px 45px rgba(15, 23, 42, 0.12);

  /* Transitions */
  --transition-fast: 120ms ease-out;
  --transition-base: 180ms ease-out;
  --transition-slow: 240ms ease-out;

  /* Layout */
  --container-max-width: 1120px;
}

/* Reduced motion adjustments */
@media (prefers-reduced-motion: reduce) {
  :root {
    --transition-fast: 0ms;
    --transition-base: 0ms;
    --transition-slow: 0ms;
  }
}

/* ========================================================================== */
/* Reset / Normalize                                                          */
/* ========================================================================== */

*, *::before, *::after {
  box-sizing: border-box;
}

html {
  -webkit-text-size-adjust: 100%;
  scroll-behavior: smooth;
}

@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }
}

body {
  margin: 0;
}

h1, h2, h3, h4, h5, h6,
p, figure, blockquote,
dl, dd {
  margin: 0;
}

ul[role='list'],
ol[role='list'] {
  list-style: none;
  padding: 0;
  margin: 0;
}

img,
picture,
video,
canvas,
svg {
  display: block;
  max-width: 100%;
}

img {
  height: auto;
}

button,
input,
select,
textarea {
  margin: 0;
  font: inherit;
  color: inherit;
}

button {
  background: none;
  border: none;
  padding: 0;
}

/* Improve text rendering */
body {
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

/* ========================================================================== */
/* Base                                                                       */
/* ========================================================================== */

body {
  font-family: var(--font-sans);
  font-size: var(--font-size-base);
  line-height: var(--line-height-relaxed);
  color: var(--color-text);
  background-color: var(--color-bg);
}

main {
  min-height: 60vh;
}

h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-heading);
  font-weight: 600;
  line-height: var(--line-height-tight);
  color: var(--gray-900);
}

h1 {
  font-size: clamp(2.25rem, 2.3vw + 1.5rem, 3rem);
  margin-bottom: var(--space-4);
}

h2 {
  font-size: clamp(1.75rem, 1.6vw + 1.1rem, 2.25rem);
  margin-bottom: var(--space-3);
}

h3 {
  font-size: clamp(1.5rem, 1.2vw + 1rem, 1.875rem);
  margin-bottom: var(--space-3);
}

h4 {
  font-size: var(--font-size-xl);
  margin-bottom: var(--space-2);
}

h5 {
  font-size: var(--font-size-lg);
  margin-bottom: var(--space-2);
}

h6 {
  font-size: var(--font-size-base);
  margin-bottom: var(--space-1);
  text-transform: uppercase;
  letter-spacing: 0.06em;
}

p {
  margin-bottom: var(--space-3);
  color: var(--color-text);
}

p:last-child {
  margin-bottom: 0;
}

small {
  font-size: var(--font-size-sm);
}

strong {
  font-weight: 600;
}

/* Links */
a {
  color: var(--color-primary);
  text-decoration: none;
  cursor: pointer;
  transition: color var(--transition-base);
}

a:hover {
  color: var(--color-primary-dark);
}

a:focus-visible {
  outline: 2px solid var(--color-primary);
  outline-offset: 3px;
  border-radius: var(--radius-sm);
}

/* Lists */
ul,
ol {
  padding-left: 1.25rem;
}

/* ========================================================================== */
/* Utilities                                                                  */
/* ========================================================================== */

/* Layout containers */

.container {
  width: 100%;
  max-width: var(--container-max-width);
  margin-inline: auto;
  padding-inline: var(--space-4);
}

@media (min-width: 1024px) {
  .container {
    padding-inline: var(--space-6);
  }
}

.section {
  padding-block: var(--space-10);
}

.section--tight {
  padding-block: var(--space-6);
}

/* Flex helpers */

.flex {
  display: flex;
}

.inline-flex {
  display: inline-flex;
}

.flex-row {
  flex-direction: row;
}

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

.flex-wrap {
  flex-wrap: wrap;
}

.items-center {
  align-items: center;
}

.items-start {
  align-items: flex-start;
}

.items-end {
  align-items: flex-end;
}

.justify-center {
  justify-content: center;
}

.justify-between {
  justify-content: space-between;
}

.gap-xs {
  gap: var(--space-2);
}

.gap-sm {
  gap: var(--space-3);
}

.gap-md {
  gap: var(--space-4);
}

.gap-lg {
  gap: var(--space-6);
}

/* Grid helpers */

.grid {
  display: grid;
}

.grid-auto-fit {
  grid-template-columns: repeat(auto-fit, minmax(0, 1fr));
}

.grid-gap-sm {
  gap: var(--space-3);
}

.grid-gap-md {
  gap: var(--space-4);
}

.grid-gap-lg {
  gap: var(--space-6);
}

/* Text alignment */

.text-left {
  text-align: left;
}

.text-center {
  text-align: center;
}

.text-right {
  text-align: right;
}

/* Visually hidden (screen reader only) */

.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;
}

/* Spacing utilities (margin-bottom only for vertical rhythm) */

.mb-0 {
  margin-bottom: 0 !important;
}

.mb-xs {
  margin-bottom: var(--space-2) !important;
}

.mb-sm {
  margin-bottom: var(--space-3) !important;
}

.mb-md {
  margin-bottom: var(--space-4) !important;
}

.mb-lg {
  margin-bottom: var(--space-6) !important;
}

/* Width / max-width helpers */

.w-full {
  width: 100%;
}

/* ========================================================================== */
/* Components                                                                 */
/* ========================================================================== */

/* Buttons */

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  padding: 0.65rem 1.4rem;
  border-radius: var(--radius-full);
  border: 1px solid transparent;
  font-size: var(--font-size-sm);
  font-weight: 500;
  line-height: 1.2;
  cursor: pointer;
  text-decoration: none;
  white-space: nowrap;
  transition:
    background-color var(--transition-base),
    color var(--transition-base),
    border-color var(--transition-base),
    box-shadow var(--transition-fast),
    transform var(--transition-fast);
}

.btn-primary {
  background-color: var(--color-primary);
  color: #ffffff;
  border-color: var(--color-primary);
  box-shadow: var(--shadow-sm);
}

.btn-primary:hover {
  background-color: var(--color-primary-dark);
  border-color: var(--color-primary-dark);
  transform: translateY(-1px);
  box-shadow: var(--shadow-md);
}

.btn-outline {
  background-color: transparent;
  color: var(--color-text);
  border-color: var(--gray-300);
}

.btn-outline:hover {
  background-color: var(--gray-100);
  border-color: var(--gray-400);
}

.btn-ghost {
  background-color: transparent;
  color: var(--color-text);
  border-color: transparent;
}

.btn-ghost:hover {
  background-color: var(--gray-100);
}

.btn:focus-visible {
  outline: 2px solid var(--color-primary);
  outline-offset: 3px;
}

.btn:disabled,
.btn[aria-disabled='true'] {
  cursor: not-allowed;
  opacity: 0.6;
  box-shadow: none;
  transform: none;
}

/* Inputs */

.input,
select,
textarea {
  width: 100%;
  padding: 0.6rem 0.8rem;
  border-radius: var(--radius-md);
  border: 1px solid var(--gray-300);
  background-color: #ffffff;
  color: var(--color-text);
  font-size: var(--font-size-sm);
  line-height: var(--line-height-normal);
  transition:
    border-color var(--transition-base),
    box-shadow var(--transition-fast),
    background-color var(--transition-fast);
}

.input::placeholder,
textarea::placeholder {
  color: var(--color-text-muted);
}

.input:focus-visible,
select:focus-visible,
textarea:focus-visible {
  outline: none;
  border-color: var(--color-primary);
  box-shadow: 0 0 0 1px var(--color-primary-soft);
}

.input[aria-invalid='true'],
input:invalid,
textarea[aria-invalid='true'],
textarea:invalid {
  border-color: var(--color-danger);
}

.input:disabled,
select:disabled,
textarea:disabled {
  background-color: var(--gray-100);
  color: var(--gray-500);
  cursor: not-allowed;
}

label {
  display: inline-block;
  margin-bottom: 0.35rem;
  font-size: var(--font-size-sm);
  color: var(--gray-700);
}

.form-help {
  margin-top: 0.25rem;
  font-size: var(--font-size-xs);
  color: var(--color-text-muted);
}

.form-error {
  margin-top: 0.25rem;
  font-size: var(--font-size-xs);
  color: var(--color-danger);
}

/* Card */

.card {
  background-color: var(--color-surface);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-sm);
  padding: var(--space-5);
  border: 1px solid var(--color-border-subtle);
}

.card--subtle {
  background-color: var(--color-surface-subtle);
  box-shadow: none;
}

.card-header {
  margin-bottom: var(--space-3);
}

.card-title {
  font-size: var(--font-size-lg);
  margin-bottom: var(--space-2);
}

.card-meta {
  font-size: var(--font-size-sm);
  color: var(--color-text-muted);
}

.card-actions {
  margin-top: var(--space-4);
  display: flex;
  gap: var(--space-3);
  align-items: center;
}

/* ========================================================================== */
/* Accessibility & Focus                                                      */
/* ========================================================================== */

:focus-visible {
  outline: 2px solid var(--color-primary);
  outline-offset: 3px;
}

/* Ensure custom focus styles are visible on dark backgrounds as well */

@media (prefers-contrast: more) {
  :focus-visible {
    outline-width: 3px;
  }
}

/* Motion sensitive users */

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
    scroll-behavior: auto !important;
  }
}