/* ==========================================================================
   EduSphere — Assignment #3, Part 1 (Media Queries)
   Team: The Ethernet (Group SE-2510)
   Used by: task1-typography.html, task2-cards.html

   NO BOOTSTRAP on these two pages — plain CSS only.

   Approach: MOBILE FIRST.
   The base rules (outside any @media) are written for phones.
   Then min-width media queries add changes for bigger screens:

       mobile  :   0px – 767px    (base styles, no media query)
       tablet  : 768px – 1023px   @media (min-width: 768px)
       desktop : 1024px and up    @media (min-width: 1024px)

   TABLE OF CONTENTS
   01. Variables and reset
   02. Page header, navigation and footer
   03. Breakpoint indicator (shows which media query is active)
   04. TASK 1 — responsive typography
   05. TASK 2 — card group (3 / 2 / 1 per row)
   06. Media queries: tablet
   07. Media queries: desktop
   ========================================================================== */


/* ==========================================================================
   01. VARIABLES AND RESET
   ========================================================================== */
:root {
  --indigo: #2f2a77;
  --indigo-light: #5b54c9;
  --amber: #f2a33c;
  --tint: #efeefc;
  --page: #f7f7fb;
  --text: #1b1c3a;
  --muted: #5a5b78;
  --border: #e2e2ef;

  --font-body: "Segoe UI", Tahoma, Verdana, Geneva, sans-serif;
  --font-heading: Georgia, "Times New Roman", serif;

  /* TASK 1: font sizes live in variables.
     Mobile values here, the media queries below overwrite them. */
  --fs-h1: 1.75rem;     /* 28px on mobile */
  --fs-h2: 1.35rem;     /* ~22px */
  --fs-h3: 1.1rem;      /* ~18px */
  --fs-body: 0.95rem;   /* ~15px */
  --fs-small: 0.8rem;

  --page-padding: 1rem;
}

* {
  box-sizing: border-box;
}

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

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

a {
  color: var(--indigo-light);
}

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

.page {
  max-width: 1140px;
  margin: 0 auto;
  padding: 1.5rem var(--page-padding);
}


/* ==========================================================================
   02. HEADER, NAVIGATION AND FOOTER
   ========================================================================== */
.site-header {
  background: var(--indigo);
  border-bottom: 3px solid var(--amber);
  color: #fff;
}

.site-header .inner {
  max-width: 1140px;
  margin: 0 auto;
  padding: 0.75rem var(--page-padding);
  display: flex;
  flex-direction: column;       /* mobile: logo above the links */
  gap: 0.75rem;
}

.brand {
  display: flex;
  align-items: center;
  gap: 0.6rem;
  color: #fff;
  text-decoration: none;
  font-family: var(--font-heading);
  font-size: 1.3rem;
  font-weight: bold;
}

.task-nav ul {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem 1rem;
}

.task-nav a {
  color: #fff;
  text-decoration: none;
  font-weight: 600;
  font-size: 0.9rem;
}

.task-nav a:hover {
  text-decoration: underline;
}

.task-nav a[aria-current="page"] {
  color: var(--amber);
}

.site-footer {
  background: var(--indigo);
  color: rgba(255, 255, 255, 0.85);
  border-top: 3px solid var(--amber);
  margin-top: 2rem;
}

.site-footer .inner {
  max-width: 1140px;
  margin: 0 auto;
  padding: 1.5rem var(--page-padding);
  font-size: var(--fs-small);
}

.site-footer h2 {
  font-family: var(--font-heading);
  color: #fff;
  font-size: 1.05rem;
  margin: 0 0 0.5rem;
}

.site-footer ul {
  margin: 0 0 1rem;
  padding-left: 1.1rem;
}


/* ==========================================================================
   03. BREAKPOINT INDICATOR
   A small label whose text is changed by the media queries — during the
   defense you resize the browser and see which query is active.
   ========================================================================== */
.breakpoint {
  display: inline-block;
  padding: 0.3rem 0.8rem;
  border-radius: 999px;
  background: var(--amber);
  color: var(--text);
  font-size: var(--fs-small);
  font-weight: 700;
}

.breakpoint::after {
  content: "Mobile view (under 768px)";
}


/* ==========================================================================
   04. TASK 1 — RESPONSIVE TYPOGRAPHY
   All sizes come from the variables in :root.
   ========================================================================== */
h1,
h2,
h3 {
  font-family: var(--font-heading);
  line-height: 1.25;
  margin: 0 0 0.6em;
}

h1 { font-size: var(--fs-h1); }
h2 { font-size: var(--fs-h2); margin-top: 1.5em; }
h3 { font-size: var(--fs-h3); }

p {
  margin: 0 0 1em;
  max-width: 70ch;           /* comfortable line length */
}

.lead {
  font-size: calc(var(--fs-body) * 1.15);
  color: var(--muted);
}

/* table that shows the current sizes next to each other */
.size-table {
  width: 100%;
  border-collapse: collapse;
  background: #fff;
  margin: 1rem 0;
  font-size: var(--fs-small);
}

.size-table caption {
  text-align: left;
  color: var(--muted);
  padding-bottom: 0.5rem;
}

.size-table th,
.size-table td {
  border: 1px solid var(--border);
  padding: 0.5rem 0.6rem;
  text-align: left;
}

.size-table thead {
  background: var(--indigo);
  color: #fff;
}

.table-wrap {
  overflow-x: auto;          /* table scrolls sideways on a small phone */
}

.sample {
  background: #fff;
  border-left: 4px solid var(--amber);
  border-radius: 8px;
  padding: 1rem 1.25rem;
  margin: 1.25rem 0;
}


/* ==========================================================================
   05. TASK 2 — CARD GROUP
   Mobile: one column, cards stacked vertically.
   ========================================================================== */
.card-grid {
  display: grid;
  grid-template-columns: 1fr;            /* mobile: 1 card per row */
  gap: 1.25rem;
  margin-top: 1.5rem;
}

.course-card {
  display: flex;
  flex-direction: column;
  background: #fff;
  border: 1px solid var(--border);
  border-radius: 12px;
  overflow: hidden;
  box-shadow: 0 6px 18px rgba(47, 42, 119, 0.1);
}

.course-card img {
  width: 100%;
  aspect-ratio: 5 / 3;
  object-fit: cover;
  background: var(--tint);
}

.course-card .body {
  display: flex;
  flex-direction: column;
  flex-grow: 1;              /* body fills the card so the button sits at the bottom */
  padding: 1rem 1.25rem 1.25rem;
}

.course-card h3 {
  margin-bottom: 0.4rem;
}

.course-card p {
  color: var(--muted);
}

.level {
  align-self: flex-start;
  background: var(--tint);
  color: var(--indigo);
  font-size: var(--fs-small);
  font-weight: 700;
  padding: 0.15rem 0.6rem;
  border-radius: 999px;
  margin-bottom: 0.6rem;
}

.card-link {
  margin-top: auto;          /* pushes the link to the bottom of the card */
  align-self: flex-start;
  background: var(--indigo);
  color: #fff;
  text-decoration: none;
  font-weight: 600;
  padding: 0.5rem 1rem;
  border-radius: 6px;
}

.card-link:hover {
  background: var(--indigo-light);
}


/* ==========================================================================
   06. MEDIA QUERY — TABLET (768px and wider)
   ========================================================================== */
@media (min-width: 768px) {
  :root {
    /* TASK 1: medium font sizes */
    --fs-h1: 2.25rem;    /* 36px */
    --fs-h2: 1.6rem;
    --fs-h3: 1.2rem;
    --fs-body: 1rem;     /* 16px */
    --fs-small: 0.85rem;
    --page-padding: 1.5rem;
  }

  .breakpoint::after {
    content: "Tablet view (768px – 1023px)";
  }

  .site-header .inner {
    flex-direction: row;               /* logo and links in one line */
    align-items: center;
    justify-content: space-between;
  }

  /* TASK 2: two cards in a row */
  .card-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}


/* ==========================================================================
   07. MEDIA QUERY — DESKTOP (1024px and wider)
   ========================================================================== */
@media (min-width: 1024px) {
  :root {
    /* TASK 1: large font sizes */
    --fs-h1: 3rem;       /* 48px */
    --fs-h2: 2rem;
    --fs-h3: 1.35rem;
    --fs-body: 1.125rem; /* 18px */
    --fs-small: 0.9rem;
    --page-padding: 2rem;
  }

  .breakpoint::after {
    content: "Desktop view (1024px and wider)";
  }

  /* TASK 2: all three cards side by side */
  .card-grid {
    grid-template-columns: repeat(3, 1fr);
  }
}