/* ======== COLOR VARIABLES AND GLOBAL SETTINGS ======= */
:root {
  --color-navy: #101828;
  --color-blue: #2563EB;
  --color-violet: #7C3AED;
  --color-background: #F8FAFC;
  --color-white: #FFFFFF;
  --color-gray: #E2E8F0;
  --color-muted: #475467;
  --color-coding-border: #BFDBFE;

  --page-background: var(--color-background);
  --text-color: var(--color-navy);
  --card-background: var(--color-white);

  --font-main: Arial, Helvetica, sans-serif;

  --radius-card: 16px;
  --page-margin: 64px;
  
  /* component colors — currently light theme */

  /* header */
  --header-background: var(--color-navy);
  --header-text: var(--color-white);
  --nav-link-color: var(--color-gray);

  /* code examples and lesson tips */
  --code-background: #F1F5F9;
  --code-text: var(--color-navy);
  --tip-background: #F5F3FF;
  --tip-border: #DDD6FE;

  /* quiz answer states */
  --answer-hover-background: #F8FAFF;
  --answer-selected-background: #EFF6FF;

  /* feedback states */
  --success-background: #F0FDF4;
  --success-border: #86EFAC;
  --success-text: #166534;

  --error-background: #FEF2F2;
  --error-border: #FCA5A5;
  --error-text: #991B1B;


}

/* makes element sizing easier to control*/
* {
  box-sizing: border-box;
}

body {
  margin: 0;
  font-family: var(--font-main);
  background-color: var(--page-background);
  color: var(--text-color);
  line-height: 1.6;
}


/* ===== SOFT DARK THEME ===== */
:root[data-theme="dark"] {
  --color-navy: #F1F5F9;
  --color-blue: #60A5FA;
  --color-violet: #A78BFA;
  --color-background: #111827;
  --color-white: #1F2937;
  --color-gray: #D1D5DB;
  --color-muted: #CBD5E1;
  --color-coding-border: #4B5563;

  --page-background: #111827;
  --text-color: #F1F5F9;
  --card-background: #1F2937;

  --header-background: #0B1220;
  --header-text: #F9FAFB;
  --nav-link-color: #D1D5DB;

  --code-background: #111827;
  --code-text: #E5E7EB;

  --tip-background: #2E2448;
  --tip-border: #6D5A9E;

  --answer-hover-background: #273449;
  --answer-selected-background: #1E3A5F;

  --success-background: #123426;
  --success-border: #2F855A;
  --success-text: #BBF7D0;

  --error-background: #451F27;
  --error-border: #9B3C4A;
  --error-text: #FECACA;
}


/* makes links inherit the design's text color */
a {
  color: inherit;
  text-decoration: none;
}

/* helps keyboard users see which element is selected */
a:focus-visible {
  outline: 3px solid var(--color-violet);
  outline-offset: 4px;
}


/* ===== HEADER AND NAVIGATION ===== */

.site-header {
  min-height: 80px;
  padding: 16px var(--page-margin);
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  background-color: var(--header-background);
  color: var(--header-text);
}

.header-actions {
  display: flex;
  align-items: center;
  gap: 24px;
}

.main-nav {
  display: flex;
  align-items: center;
  gap: 32px;
}

.main-nav a {
  font-size: 15px;
  color: var(--nav-link-color);
  transition: color 0.2s ease;
}

.main-nav a:hover {
  color: var(--header-text);
}

.theme-toggle {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  min-height: 42px;
  padding: 9px 14px;
  border: 1px solid #667085;
  border-radius: 999px;
  background: transparent;
  color: var(--header-text);
  font: inherit;
  font-size: 14px;
  font-weight: 600;
  cursor: pointer;
  transition: background-color 0.2s ease, border-color 0.2s ease;
}

.theme-toggle:hover {
  background-color: #344054;
  border-color: #98A2B3;
}

.theme-toggle:focus-visible {
  outline: 3px solid #A5B4FC;
  outline-offset: 4px;
}

.theme-toggle-icon {
  font-size: 18px;
  line-height: 1;
}


.logo {
  display: inline-flex;
  align-items: center;
  gap: 10px;

  font-size: 20px;
  font-weight: 700;
}

.logo-icon {
  color: #A5B4FC;
  font-size: 28px;
}

.main-nav {
  display: flex;
  align-items: center;
  gap: 32px;
}

.main-nav a {
  font-size: 15px;
  color: #E2E8F0;
  transition: color 0.2s ease;
}

.main-nav a:hover {
  color: var(--color-white);
}


/* ===== HERO SECTION ==== */

.hero {
  padding: 80px 24px 72px;
  text-align: center;
}

.eyebrow {
  margin: 0 0 16px;

  color: var(--color-violet);
  font-size: 12px;
  font-weight: 700;
  letter-spacing: 1.8px;
}

.hero h1 {
  max-width: 800px;
  margin: 0 auto;

  font-size: clamp(36px, 5vw, 56px);
  line-height: 1.15;
  letter-spacing: -1.5px;
}

.hero-description {
  max-width: 540px;
  margin: 20px auto 28px;

  color: var(--color-muted);
  font-size: 18px;
}

.primary-button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 10px;

  min-height: 48px;
  padding: 12px 24px;

  border: 2px solid var(--color-blue);
  border-radius: 10px;

  background-color: var(--color-blue);
  color: var(--color-white);

  font-size: 15px;
  font-weight: 700;

  transition:
    background-color 0.2s ease,
    transform 0.2s ease;
}

.primary-button:hover {
  background-color: #1D4ED8;
  transform: translateY(-2px);
}


/* ===== TOPIC SECTION ==== */

.topics-section {
  max-width: 1440px;
  margin: 0 auto;
  padding: 24px var(--page-margin) 88px;
}

.section-heading {
  margin-bottom: 32px;
}

.section-heading h2 {
  margin: 0 0 8px;
  font-size: 28px;
  line-height: 1.3;
}

.section-heading p {
  margin: 0;
  color: var(--color-muted);
}


/* ====== TOPIC CARD GRID ===== */
.topic-grid {
  display: grid;

  /* three equal-width columns on wide screens */
  grid-template-columns: repeat(3, minmax(0, 1fr));

  gap: 24px;
}

.topic-card {
  min-width: 0;
  padding: 24px;

  border: 1px solid var(--color-gray);
  border-radius: var(--radius-card);

  background-color: var(--card-background);

  display: flex;
  flex-direction: column;
  align-items: flex-start;

  transition:
    transform 0.2s ease,
    box-shadow 0.2s ease;
}

.topic-card:hover {
  transform: translateY(-3px);
  box-shadow: 0 8px 24px rgb(16 24 40 / 8%);
}

.topic-icon {
  width: 48px;
  height: 48px;
  margin-bottom: 20px;

  display: flex;
  align-items: center;
  justify-content: center;

  border-radius: 12px;
  font-size: 24px;
  font-weight: 700;
}

.coding-icon {
  background-color: #DBEAFE;
  color: var(--color-blue);
}

.science-icon {
  background-color: #EDE9FE;
  color: var(--color-violet);
}

.math-icon {
  background-color: #DBEAFE;
  color: #1D4ED8;
}

.topic-card h3 {
  margin: 0 0 4px;
  font-size: 22px;
  line-height: 1.4;
}

.topic-card p {
  margin: 0 0 24px;
  color: var(--color-muted);
  font-size: 15px;
}

.topic-link {
  display: inline-flex;
  align-items: center;
  gap: 8px;

  margin-top: auto;
  color: var(--color-blue);
  font-size: 15px;
  font-weight: 700;
}

.topic-link:hover {
  color: var(--color-violet);
}


/* ===== FOOTER ==== */

.site-footer {
  padding: 24px var(--page-margin);

  border-top: 1px solid var(--color-gray);
  text-align: center;
  color: var(--color-muted);
  font-size: 14px;
}

.site-footer p {
  margin: 0;
}


/* ===== LESSON SCREEN ===== */

/* keep hidden screens hidden even when other styles apply */
[hidden] {
  display: none !important;
}

.lesson-content {
  width: 100%;
  max-width: 1000px;
  margin: 0 auto;
  padding: 40px 32px 80px;
}

.breadcrumbs {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 10px;
  margin-bottom: 32px;
  color: var(--color-muted);
  font-size: 14px;
}

.breadcrumbs a {
  color: var(--color-blue);
  font-weight: 600;
}

.lesson-progress {
  display: flex;
  flex-direction: column;
  gap: 10px;
  margin-bottom: 40px;
  color: var(--color-muted);
  font-size: 14px;
}

.progress-track {
  width: 100%;
  height: 6px;
  overflow: hidden;
  border-radius: 999px;
  background-color: var(--color-gray);
}

.progress-fill {
  width: 33.333%;
  height: 100%;
  border-radius: inherit;
  background-color: var(--color-blue);
}

.lesson-heading {
  margin-bottom: 36px;
}

.lesson-heading h1 {
  margin: 0 0 16px;
  font-size: clamp(32px, 5vw, 48px);
  line-height: 1.2;
  letter-spacing: -1px;
}

.lesson-heading > p:last-child {
  max-width: 650px;
  margin: 0;
  color: var(--color-muted);
  font-size: 18px;
}

.lesson-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 24px;
}

.lesson-card {
  min-width: 0;
  padding: 24px;
  border: 1px solid var(--color-gray);
  border-radius: var(--radius-card);
  background-color: var(--card-background);
}

.lesson-number {
  margin-bottom: 16px;
  color: var(--color-violet);
  font-size: 14px;
  font-weight: 700;
}

.lesson-card h2 {
  margin: 0 0 8px;
  font-size: 24px;
}

.lesson-card > p {
  min-height: 52px;
  margin: 0 0 24px;
  color: var(--color-muted);
}

.code-example {
  display: flex;
  flex-direction: column;
  gap: 8px;
  padding: 20px;
  overflow-wrap: anywhere;
  border: 1px solid var(--color-coding-border);
  border-radius: 10px;
  background-color: var(--code-background);
  color: var(--code-text);
  font-family: monospace;
  font-size: 14px;
}

.code-label {
  margin-bottom: 4px;
  color: var(--color-muted);
  font-family: var(--font-main);
  font-size: 11px;
  font-weight: 700;
  letter-spacing: 1px;
}

.lesson-tip {
  display: flex;
  align-items: flex-start;
  gap: 16px;
  margin-top: 24px;
  padding: 24px;
  border: 1px solid var(--tip-border);
  border-radius: 12px;
  background-color: var(--tip-background);
  color: var(--color-navy);
}

.tip-icon {
  color: var(--color-violet);
  font-size: 24px;
}

.lesson-tip h2 {
  margin: 0 0 6px;
  font-size: 17px;
}

.lesson-tip p {
  margin: 0;
  line-height: 1.7;
}

.lesson-actions {
  display: flex;
  justify-content: flex-end;
  margin-top: 32px;
}


/* tablet spacing for the lesson */
@media (min-width: 601px) and (max-width: 900px) {
  .lesson-content {
    padding: 32px 24px 64px;
  }

  .site-header {
    gap: 16px;
  }

  .header-actions {
    gap: 16px;
  }

  .main-nav {
    gap: 20px;
  }

}

/* stack the concept cards on smaller screens*/
@media (max-width: 600px) {
  .lesson-content {
    padding: 28px 20px 56px;
  }

  .breadcrumbs {
    gap: 7px;
    margin-bottom: 24px;
    font-size: 12px;
  }

  .lesson-progress {
    margin-bottom: 32px;
  }

  .lesson-grid {
    grid-template-columns: 1fr;
    gap: 16px;
  }

  .lesson-card > p {
    min-height: 0;
  }

  .lesson-tip {
    padding: 18px;
  }

  .lesson-actions .primary-button {
    width: 100%;
  }

  .site-header {
    align-items: flex-start;
    flex-wrap: wrap;
    gap: 16px;
  }

  .header-actions {
    width: 100%;
    justify-content: space-between;
    flex-wrap: wrap;
    gap: 12px;
  }

  .main-nav {
    gap: 18px;
  }

  .theme-toggle {
    min-height: 40px;
    padding: 8px 12px;
  }
}


/* ======== QUIZ SCREEN ======== */

.quiz-content {
  width: 100%;
  max-width: 850px;
  margin: 0 auto;
  padding: 40px 24px 80px;
}

/* quiz progress and labels */
.quiz-progress {
  margin-bottom: 40px;
}

.quiz-progress-labels {
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 12px;
  margin-bottom: 14px;
}

.quiz-progress-labels .eyebrow {
  margin: 0;
}

#question-count {
  color: var(--color-muted);
  font-size: 14px;
  font-weight: 600;
}

#quiz-progress-fill {
  width: 33.333%;
  transition: width 0.3s ease;
}

/* question heading */
.quiz-heading {
  margin-bottom: 32px;
}

.quiz-heading h1 {
  margin: 0 0 12px;
  font-size: clamp(30px, 5vw, 42px);
  line-height: 1.2;
  letter-spacing: -1px;
}

.quiz-heading p {
  margin: 0;
  color: var(--color-muted);
  font-size: 16px;
  line-height: 1.6;
}

/* main question card */
.quiz-card {
  padding: 32px;
  border: 1px solid var(--color-gray);
  border-radius: var(--radius-card);
  background-color: var(--card-background);
  box-shadow: 0 8px 24px rgba(16, 24, 40, 0.04);
}

/* remove the browser's default fieldset styling */
.answer-group {
  min-width: 0;
  margin: 0;
  padding: 0;
  border: 0;
}

.answer-group legend {
  display: block;
  width: 100%;
  margin-bottom: 24px;
  color: var(--text-color);
  font-size: 20px;
  font-weight: 700;
  line-height: 1.6;
}

/* stack the answer choices */
.answer-options {
  display: flex;
  flex-direction: column;
  gap: 14px;
}

/* individual answer choice */
.answer-option {
  display: flex;
  align-items: flex-start;
  gap: 14px;
  padding: 18px;
  border: 1px solid var(--color-gray);
  border-radius: 12px;
  background-color: var(--card-background);
  cursor: pointer;
  transition:
    border-color 0.2s ease,
    background-color 0.2s ease,
    box-shadow 0.2s ease;
}

/* hover effect */
.answer-option:hover {
  border-color: var(--color-blue);
  background-color: #F8FAFF;
}

/* highlight the selected answer */
.answer-option:has(input:checked) {
  border-color: var(--color-blue);
  background-color: var(--answer-selected-background);
  box-shadow: 0 0 0 1px var(--color-blue);
}

/* make keyboard selection visible */
.answer-option:focus-within {
  outline: 3px solid var(--color-violet);
  outline-offset: 3px;
}

/* native radio button */
.answer-option input[type="radio"] {
  flex-shrink: 0;
  width: 18px;
  height: 18px;
  margin: 3px 0 0;
  accent-color: var(--color-blue);
  cursor: pointer;
}

/* A, B, C answer markers */
.answer-letter {
  display: flex;
  flex-shrink: 0;
  align-items: center;
  justify-content: center;
  width: 30px;
  height: 30px;
  border: 1px solid var(--color-gray);
  border-radius: 8px;
  color: var(--color-muted);
  font-size: 13px;
  font-weight: 700;
}

.answer-option:has(input:checked) .answer-letter {
  border-color: var(--color-blue);
  background-color: var(--color-blue);
  color: var(--color-white);
}

.answer-text {
  padding-top: 4px;
  color: var(--text-color);
  line-height: 1.6;
}

/* feedback area: javascript will show this after checking */
.quiz-feedback {
  margin-top: 24px;
  padding: 18px 20px;
  border: 1px solid var(--color-gray);
  border-radius: 12px;
  line-height: 1.6;
}

.quiz-feedback.correct {
  border-color: var(--success-border);
  background-color: var(--success-background);
  color: var(--success-text);
}

.quiz-feedback.incorrect {
  border-color: var(--error-border);
  background-color: var(--error-background);
  color: var(--error-text);
}

/* quiz button */
.quiz-actions {
  display: flex;
  justify-content: flex-end;
  margin-top: 28px;
}

.quiz-actions .primary-button {
  border: none;
  cursor: pointer;
}

/* disabled button after an answer is submitted */
.quiz-actions .primary-button:disabled {
  cursor: not-allowed;
  opacity: 0.6;
  transform: none;
}

/* smaller screens */
@media (max-width: 600px) {
  .quiz-content {
    padding: 28px 20px 56px;
  }

  .quiz-progress {
    margin-bottom: 32px;
  }

  .quiz-heading {
    margin-bottom: 24px;
  }

  .quiz-card {
    padding: 20px;
  }

  .answer-group legend {
    font-size: 18px;
  }

  .answer-option {
    gap: 10px;
    padding: 14px;
  }

  .quiz-actions .primary-button {
    width: 100%;
  }
}

/* respect reduced-motion preferences */
@media (prefers-reduced-motion: reduce) {
  #quiz-progress-fill,
  .answer-option {
    transition: none;
  }
}

/* ========== COMPLETION SCREEN ======== */

.completion-screen {
  min-height: calc(100vh - 140px);
  display: flex;
  justify-content: center;
  align-items: center;
  padding: 48px 24px 64px;
}

.completion-content {
  width: 100%;
  max-width: 620px;
  margin: 0 auto;
  text-align: center;
}

/* green success icon */

.completion-icon {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 76px;
  height: 76px;
  margin: 0 auto 24px;
  border-radius: 50%;
  background-color: #DCFCE7;
  color: #15803D;
  font-size: 38px;
  font-weight: 700;
}

/* completion heading */

.completion-content > .eyebrow {
  margin-bottom: 12px;
  color: #15803D;
  font-size: 12px;
  font-weight: 700;
  letter-spacing: 1.5px;
}

.completion-content h1 {
  margin: 0 0 16px;
  color: var(--text-color);
  font-size: clamp(30px, 5vw, 42px);
  line-height: 1.2;
}

.completion-description {
  max-width: 460px;
  margin: 0 auto 32px;
  color: var(--color-muted);
  font-size: 16px;
  line-height: 1.7;
}

/* score card */

.completion-score {
  margin-bottom: 28px;
  padding: 28px 24px;
  border: 1px solid var(--color-gray);
  border-radius: var(--radius-card);
  background-color: var(--card-background);
}

.score-label {
  margin: 0 0 12px;
  color: var(--color-muted);
  font-size: 12px;
  font-weight: 700;
  letter-spacing: 1px;
}

.score-value {
  display: flex;
  align-items: baseline;
  justify-content: center;
  gap: 8px;
  margin: 0 0 12px;
  color: var(--text-color);
  font-size: 48px;
  font-weight: 700;
}

.score-divider {
  color: #98A2B3;
  font-size: 36px;
  font-weight: 400;
}

.completion-message {
  margin: 0;
  color: var(--color-muted);
  font-size: 14px;
  line-height: 1.6;
}

/* lesson progress bar */

.completion-progress {
  margin-bottom: 32px;
  text-align: left;
}

.completion-progress-labels {
  display: flex;
  justify-content: space-between;
  gap: 16px;
  margin-bottom: 10px;
  color: var(--text-color);
  font-size: 14px;
  font-weight: 600;
}

.completion-progress .progress-track {
  height: 10px;
  overflow: hidden;
  border-radius: 999px;
  background-color: var(--color-gray);
}

.completion-progress .progress-fill {
  width: 0;
  height: 100%;
  border-radius: inherit;
  background-color: #16A34A;
  transition: width 400ms ease;
}

/* completion buttons */

.completion-actions {
  display: flex;
  flex-direction: column;
  align-items: stretch;
  gap: 12px;
}

.completion-actions .primary-button,
.completion-actions .secondary-button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  width: 100%;
  min-height: 48px;
  padding: 12px 20px;
  border-radius: 10px;
  font: inherit;
  font-size: 15px;
  font-weight: 600;
  cursor: pointer;
}

.completion-actions .secondary-button {
  border: 1px solid var(--color-gray);
  background-color: var(--card-background);
  color: var(--text-color);
}

.completion-actions .secondary-button:hover {
  border-color: var(--color-blue);
  color: var(--color-blue);
}

.completion-actions button:focus-visible {
  outline: 3px solid var(--color-violet);
  outline-offset: 4px;
}

/* smaller screens */

@media (max-width: 600px) {
  .completion-screen {
    min-height: auto;
    padding: 36px 20px 48px;
  }

  .completion-icon {
    width: 64px;
    height: 64px;
    margin-bottom: 20px;
    font-size: 32px;
  }

  .completion-score {
    padding: 24px 18px;
  }

  .score-value {
    font-size: 42px;
  }
}

/* respect reduced-motion preferences */

@media (prefers-reduced-motion: reduce) {
  .completion-progress .progress-fill {
    transition: none;
  }
}


/* ======== RESPONSIVE LAYOUTS ====== */

/* tablets and smaller laptops */
@media (max-width: 900px) {
  :root {
    --page-margin: 32px;
  }

  .hero {
    padding-top: 64px;
  }

  .topic-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
}

/* phones*/
@media (max-width: 600px) {
  :root {
    --page-margin: 20px;
  }

  .site-header {
    padding-top: 16px;
    padding-bottom: 16px;
    flex-wrap: wrap;
    gap: 12px;
  }

  .logo {
    font-size: 18px;
  }

  .main-nav {
    gap: 20px;
  }

  .main-nav a {
    font-size: 14px;
  }

  .hero {
    padding: 56px 20px 48px;
  }

  .hero h1 {
    font-size: clamp(32px, 8vw, 42px);
    letter-spacing: -0.8px;
  }

  .hero-description {
    font-size: 16px;
  }

  .topics-section {
    padding-top: 16px;
    padding-bottom: 56px;
  }

  .section-heading h2 {
    font-size: 24px;
  }

  .topic-grid {
    grid-template-columns: 1fr;
    gap: 16px;
  }

  .topic-card {
    padding: 24px;
  }

  .site-footer {
    padding-top: 24px;
    padding-bottom: 24px;
  }
}


/* ====== CLICKABLE ELEMENTS AND HOVER STATES ===== */

/* show a pointer when hovering over clickable elements */
a,
button,
[role="button"],
input[type="button"],
input[type="submit"],
select,
label[for] {
  cursor: pointer;
}

/* give links a subtle hover response */
a:hover {
  text-decoration-thickness: 2px;
}

/* make buttons feel interactive */
button,
.primary-button {
  transition:
    background-color 0.2s ease,
    color 0.2s ease,
    box-shadow 0.2s ease,
    transform 0.2s ease;
}

button:hover,
.primary-button:hover {
  transform: translateY(-2px);
}

/* keep keyboard navigation visible */
a:focus-visible,
button:focus-visible {
  outline: 3px solid var(--color-violet);
  outline-offset: 4px;
}

/* avoid hover movement on touch devices */
@media (hover: none) {
  button:hover,
  .primary-button:hover {
    transform: none;
  }
}

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



/* ===== LESSON SCREEN SPACING FIX ===== */

.lesson-screen {
  box-sizing: border-box;
  padding: 32px 64px 48px;
}

@media (max-width: 900px) {
  .lesson-screen {
    padding: 28px 32px 40px;
  }
}

@media (max-width: 600px) {
  .lesson-screen {
    padding: 24px 20px 32px;
  }
}


/* ===== DARK THEME: QUIZ ANSWER CONTRAST FIX ===== */
:root[data-theme="dark"] .answer-option {
  background-color: #1F2937;
  color: #F9FAFB;
  border-color: #475569;
}

:root[data-theme="dark"] .answer-option:hover {
  background-color: #334155;
  color: #FFFFFF;
  border-color: #64748B;
}

:root[data-theme="dark"] .answer-option:has(input:checked) {
  background-color: #1E3A5F;
  color: #FFFFFF;
  border-color: #60A5FA;
}

:root[data-theme="dark"] .answer-option:focus-within {
  outline: 3px solid #A5B4FC;
  outline-offset: 3px;
}

:root[data-theme="dark"] .answer-option input {
  accent-color: #60A5FA;
}



/* ======= MY PROGRESS DASHBOARD ====== */

.progress-page {
  width: min(100% - 40px, 900px);
  margin: 0 auto;
  padding: 48px 0 64px;
}

.progress-page > h1 {
  margin: 0 0 16px;
  font-size: clamp(32px, 5vw, 44px);
  line-height: 1.2;
  letter-spacing: -1px;
}

.progress-intro {
  max-width: 600px;
  margin: 0 0 32px;
  color: var(--color-muted);
  line-height: 1.7;
}

.progress-overview {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 24px;
  margin: 28px 0 36px;
}

.progress-stat,
.progress-topic-card {
  min-width: 0;
  padding: 24px;
  border: 1px solid var(--color-gray);
  border-radius: var(--radius-card);
  background-color: var(--card-background);
}

.progress-stat {
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.progress-stat-label {
  color: var(--color-muted);
  font-size: 14px;
}

.progress-stat strong {
  font-size: 30px;
  line-height: 1.3;
}

.progress-topic-list {
  display: grid;
  gap: 16px;
  margin: 24px 0 32px;
}

.progress-topic-card {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 20px;
  transition: border-color 0.2s ease, transform 0.2s ease;
}

.progress-topic-card:hover {
  border-color: var(--color-blue);
  transform: translateY(-2px);
}

.progress-topic-card h2 {
  margin: 0 0 6px;
  font-size: 20px;
  line-height: 1.4;
}

.progress-topic-card p {
  margin: 0;
  color: var(--color-muted);
  font-size: 14px;
  line-height: 1.6;
}

.progress-topic-card > strong {
  flex-shrink: 0;
  color: var(--color-blue);
  font-size: 15px;
  text-align: right;
}

#progress-learn-button {
  cursor: pointer;
}

#progress-learn-button:focus-visible {
  outline: 3px solid var(--color-violet);
  outline-offset: 4px;
}

/* tablet and mobile layouts */
@media (max-width: 600px) {
  .progress-page {
    width: calc(100% - 40px);
    padding: 32px 0 48px;
  }

  .progress-overview {
    grid-template-columns: 1fr;
    gap: 16px;
    margin: 24px 0 32px;
  }

  .progress-stat,
  .progress-topic-card {
    padding: 20px;
  }

  .progress-stat strong {
    font-size: 26px;
  }

  .progress-topic-card {
    gap: 12px;
  }

  .progress-topic-card h2 {
    font-size: 18px;
  }

  .progress-topic-card > strong {
    max-width: 45%;
    font-size: 14px;
  }

  #progress-learn-button {
    width: 100%;
  }
}

/* respect reduced-motion preferences */
@media (prefers-reduced-motion: reduce) {
  .progress-topic-card {
    transition: none;
  }

  .progress-topic-card:hover {
    transform: none;
  }
}