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

:root {
  /* Colors */
  --color-bg: #f6f9fc;
  --color-surface: #ffffff;
  --color-text: #1f2933;
  --color-text-muted: #6b7280;

  --color-primary: #2563eb; /* calming blue */
  --color-primary-soft: #e0edff;
  --color-primary-strong: #1d4ed8;

  --color-success: #059669;
  --color-warning: #d97706;
  --color-danger: #dc2626;

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

  /* Typography */
  --font-sans: system-ui, -apple-system, BlinkMacSystemFont, "SF Pro Text", "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  --font-heading: "Inter", system-ui, -apple-system, BlinkMacSystemFont, "SF Pro Display", "Segoe UI", Roboto, Helvetica, Arial, sans-serif;

  --font-size-xs: 0.75rem;   /* 12px */
  --font-size-sm: 0.875rem;  /* 14px */
  --font-size-md: 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 */
  --font-size-5xl: 3rem;     /* 48px */

  --line-height-tight: 1.2;
  --line-height-snug: 1.35;
  --line-height-normal: 1.6;
  --line-height-relaxed: 1.8;

  /* 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-xs: 0.1875rem;  /* 3px */
  --radius-sm: 0.25rem;    /* 4px */
  --radius-md: 0.5rem;     /* 8px */
  --radius-lg: 0.75rem;    /* 12px */
  --radius-xl: 1rem;       /* 16px */
  --radius-pill: 9999px;

  /* Shadows (soft, educational, non-harsh) */
  --shadow-xs: 0 1px 2px rgba(15, 23, 42, 0.04);
  --shadow-sm: 0 1px 3px rgba(15, 23, 42, 0.08), 0 1px 2px rgba(15, 23, 42, 0.06);
  --shadow-md: 0 4px 12px rgba(15, 23, 42, 0.08);
  --shadow-lg: 0 12px 30px rgba(15, 23, 42, 0.12);

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

  /* Layout */
  --container-max-width: 1120px;
  --container-padding-x: 1.5rem;
}

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

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

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

body {
  margin: 0;
}

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

ul, ol {
  margin: 0;
  padding: 0;
}

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

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

img {
  height: auto;
}

a {
  color: inherit;
  text-decoration: none;
}

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

fieldset {
  border: 0;
  margin: 0;
  padding: 0;
}

textarea {
  resize: vertical;
}

:focus {
  outline: none;
}

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

body {
  font-family: var(--font-sans);
  font-size: var(--font-size-md);
  line-height: var(--line-height-normal);
  color: var(--color-text);
  background-color: var(--color-bg);
  text-rendering: optimizeLegibility;
  -webkit-font-smoothing: antialiased;
}

main {
  min-height: 60vh;
}

/* Headings - modern, clear hierarchy */

h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-heading);
  font-weight: 700;
  color: var(--color-gray-900);
  line-height: var(--line-height-tight);
}

h1 {
  font-size: var(--font-size-4xl);
  letter-spacing: -0.02em;
  margin-bottom: var(--space-4);
}

h2 {
  font-size: var(--font-size-3xl);
  letter-spacing: -0.02em;
  margin-bottom: var(--space-3);
}

h3 {
  font-size: var(--font-size-2xl);
  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-md);
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--color-text-muted);
  margin-bottom: var(--space-2);
}

p {
  margin-bottom: var(--space-4);
  color: var(--color-text);
  max-width: 70ch; /* comfortable reading width */
}

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

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

strong {
  font-weight: 600;
}

/* Links - subtle, trustworthy */

a {
  color: var(--color-primary);
  text-decoration: none;
  transition: color var(--transition-normal),
              text-decoration-color var(--transition-normal);
  text-decoration-thickness: 1px;
  text-underline-offset: 0.18em;
}

a:hover {

  text-decoration: underline;
}

/* Lists */

ul, ol {
  padding-left: 1.5rem;
  margin-bottom: var(--space-4);
}



/* Sections */

section {
  padding-block: var(--space-12);
}

@media (min-width: 768px) {
  section {
    padding-block: var(--space-16);
  }
}

/* =========================================================
   Accessibility & Motion
   ========================================================= */

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

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

/* 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;
}

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

/* Container */

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

/* Flex helpers */

.flex {
  display: flex;
}

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

.flex-center {
  display: flex;
  align-items: center;
  justify-content: center;
}

.flex-between {
  display: flex;
  align-items: center;
  justify-content: space-between;
}

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

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

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

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

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

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

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

/* Grid helpers */

.grid {
  display: grid;
}

.grid-2 {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: var(--space-6);
}

.grid-3 {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: var(--space-6);
}

@media (max-width: 768px) {
  .grid-2,
  .grid-3 {
    grid-template-columns: minmax(0, 1fr);
  }
  .flex-between{
    flex-direction: column;
  }
}

/* Width constraints for content blocks */

.content-narrow {
  max-width: 48rem;
}

/* Simple spacing utilities for vertical rhythm */

.mt-0 { margin-top: 0 !important; }
.mt-sm { margin-top: var(--space-3) !important; }
.mt-md { margin-top: var(--space-4) !important; }
.mt-lg { margin-top: var(--space-8) !important; }

.mb-0 { margin-bottom: 0 !important; }
.mb-sm { margin-bottom: var(--space-3) !important; }
.mb-md { margin-bottom: var(--space-4) !important; }
.mb-lg { margin-bottom: var(--space-8) !important; }

.text-center { text-align: center !important; }
.text-right { text-align: right !important; }

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

/* Buttons - primary CTA for enrollment / trial lessons */

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.4rem;
  padding: 0.65rem 1.25rem;
  border-radius: var(--radius-pill);
  border: 1px solid transparent;
  font-weight: 600;
  font-size: var(--font-size-sm);
  line-height: 1.2;
  cursor: pointer;
  transition: background-color var(--transition-normal),
              color var(--transition-normal),
              border-color var(--transition-normal),
              box-shadow var(--transition-normal),
              transform var(--transition-fast);
  text-decoration: none;
  white-space: nowrap;
}

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


.btn-primary:active {
  transform: translateY(0);
  box-shadow: var(--shadow-xs);
}

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

.btn-secondary:hover {
  background-color: var(--color-primary-soft);
  border-color: var(--color-primary);
  box-shadow: var(--shadow-sm);
}

.btn-ghost {
  background-color: transparent;
  color: var(--color-primary);
  border-radius: var(--radius-pill);
  padding-inline: 0.5rem;
}

.btn-ghost:hover {
  background-color: rgba(37, 99, 235, 0.06);
}

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

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

/* Inputs - consistent, calm fields for forms */

.input,
select,
textarea {
  width: 100%;
  padding: 0.65rem 0.8rem;
  border-radius: var(--radius-md);
  border: 1px solid var(--color-gray-200);
  background-color: #ffffff;
  font: inherit;
  color: var(--color-text);
  transition: border-color var(--transition-normal),
              box-shadow var(--transition-normal),
              background-color var(--transition-normal);
}

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

.input:focus-visible,
select:focus-visible,
textarea:focus-visible {
  border-color: var(--color-primary);
  box-shadow: 0 0 0 1px var(--color-primary-soft);
  outline: 2px solid var(--color-primary);
  outline-offset: 1px;
}

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

label {
  display: inline-block;
  margin-bottom: 0.35rem;
  font-weight: 500;
}

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

/* Card - used for course levels, pricing, teacher profiles */

.card {
  background-color: var(--color-surface);
  border-radius: var(--radius-lg);
  padding: var(--space-6);
  box-shadow: var(--shadow-sm);
  border: 1px solid rgba(148, 163, 184, 0.16);
}

.card-header {
  margin-bottom: var(--space-4);
}

.card-title {
  font-family: var(--font-heading);
  font-size: var(--font-size-xl);
  font-weight: 600;
  margin-bottom: 0.25rem;
}

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

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

.card-footer {
  margin-top: var(--space-4);
}

/* Tag / pill - e.g. difficulty level, format (online/offline) */

.badge {
  display: inline-flex;
  align-items: center;
  padding: 0.2rem 0.6rem;
  border-radius: var(--radius-pill);
  font-size: var(--font-size-xs);
  font-weight: 500;
  background-color: var(--color-primary-soft);
  color: var(--color-primary-strong);
}

.badge-muted {
  background-color: var(--color-gray-100);
  color: var(--color-gray-700);
}

/* Hero / page section helpers (non-opinionated) */

.hero {
  padding-block: var(--space-16);
}

@media (min-width: 768px) {
  .hero {
    padding-block: var(--space-20);
  }
}

.hero-title {
  font-size: clamp(2.2rem, 3vw, 2.8rem);
  line-height: var(--line-height-tight);
}

.hero-subtitle {
  font-size: var(--font-size-lg);
  color: var(--color-text-muted);
  max-width: 36rem;
}

/* Simple chip list for key features / benefits */

.chip-list {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
}

.chip {
  padding: 0.3rem 0.75rem;
  border-radius: var(--radius-pill);
  background-color: #ffffff;
  border: 1px solid var(--color-gray-200);
  font-size: var(--font-size-xs);
  color: var(--color-gray-700);
}

/* Tables - for schedules and pricing */

table {
  width: 100%;
  border-collapse: collapse;
  font-size: var(--font-size-sm);
}

thead {
  background-color: #f1f5f9;
}

th, td {
  padding: 0.75rem 1rem;
  text-align: left;
}

th {
  font-weight: 600;
  color: var(--color-gray-700);
}

tbody tr:nth-child(even) {
  background-color: #f9fafb;
}

tbody tr:hover {
  background-color: #eef2ff;
}

/* Alerts / info boxes - for important course information */

.alert {
  padding: 0.85rem 1rem;
  border-radius: var(--radius-md);
  font-size: var(--font-size-sm);
  display: flex;
  gap: 0.5rem;
  align-items: flex-start;
}

.alert-info {
  background-color: #eff6ff;
  color: #1d4ed8;
  border: 1px solid #bfdbfe;
}

.alert-success {
  background-color: #ecfdf3;
  color: #047857;
  border: 1px solid #bbf7d0;
}

.alert-warning {
  background-color: #fffbeb;
  color: #b45309;
  border: 1px solid #fcd34d;
}

.alert-danger {
  background-color: #fef2f2;
  color: #b91c1c;
  border: 1px solid #fecaca;
}

/* Footer basics */

.footer {
  font-size: var(--font-size-sm);
  color: var(--color-text-muted);
  padding-block: var(--space-8);
}

.footer a {
  color: inherit;
}

.footer a:hover {
  color: var(--color-primary-strong);
  text-decoration: underline;
}