/* ---------------------------
   Base
---------------------------- */
:root {
    --brand-900: #0b3b66;
    /* deep navy header for better contrast */
    --brand-700: #114a80;
    --ink: #1f2937;
    --muted: #6b7280;
    --paper: #ffffff;
    --bg: #f5f7fb;
    --border: #e5e7eb;
    --accent: #2563eb;
    /* link color */
    --accent-ink: #0b3b66;
    --ok: #22c55e;
}

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

html,
body {
    height: 100%;
    margin: 0;
}

body {
    font-family: "Segoe UI", system-ui, -apple-system, Arial, sans-serif;
    color: var(--ink);
    background: var(--bg);
    line-height: 1.6;
    -webkit-font-smoothing: antialiased;
    text-rendering: optimizeLegibility;
}

/* ---------------------------
   Header
---------------------------- */
.site-header {
    background: linear-gradient(180deg, var(--brand-900), var(--brand-700));
    color: #fff;
    padding: 2.5rem 1rem;
    box-shadow: 0 4px 16px rgba(0, 0, 0, .2);
}

.header-inner {
    max-width: 960px;
    margin: 0 auto;
    text-align: center;
}

.site-header h1 {
    margin: 0 0 .5rem;
    font-size: clamp(1.6rem, 2.5vw, 2.2rem);
    letter-spacing: .2px;
}

.cohort-line,
.playlist-line {
    margin: .35rem 0;
}

.site-header a {
    color: #fff;
    text-decoration: underline;
    text-underline-offset: 2px;
}

/* Button style for playlist link */
.btn {
    display: inline-block;
    border-radius: 999px;
    padding: .55rem 1rem;
    font-weight: 600;
    text-decoration: none;
    border: 2px solid rgba(255, 255, 255, .85);
}

.btn-light {
    background: #ffffff;
    border-color: #ffffff;
    color: var(--accent-ink);
    text-decoration: none;
}

/* ---------------------------
   Layout
---------------------------- */
.container {
    max-width: 960px;
    margin: 2rem auto;
    padding: 0 1rem;
}

.card {
    background: var(--paper);
    border: 1px solid var(--border);
    border-radius: 12px;
    padding: 1.25rem 1.25rem 1.5rem;
    box-shadow: 0 2px 12px rgba(0, 0, 0, .05);
    margin-bottom: 1.25rem;
}

h2 {
    color: var(--brand-900);
    font-size: clamp(1.2rem, 2vw, 1.4rem);
    margin: .25rem 0 1rem;
}

/* ---------------------------
   Student form
---------------------------- */
.student-form {
    display: grid;
    gap: .85rem;
    grid-template-columns: 1fr 1fr;
}

.field {
    display: grid;
    gap: .35rem;
}

.field label {
    font-weight: 600;
}

.field input {
    border: 1px solid var(--border);
    border-radius: 10px;
    padding: .6rem .75rem;
    font-size: 1rem;
    background: #fff;
}

@media (max-width: 720px) {
    .student-form {
        grid-template-columns: 1fr;
    }
}

/* ---------------------------
   Notes / Answers
---------------------------- */
.notes-area,
.answer {
    width: 100%;
    border: 1px solid var(--border);
    border-radius: 10px;
    padding: .75rem .9rem;
    font-size: 0.98rem;
    background: #fff;
    resize: vertical;
}

.steps {
    margin: 0 0 .5rem 1rem;
    padding-left: 1rem;
}

.callout {
    background: #f0f6ff;
    border: 1px solid #dbeafe;
    border-radius: 10px;
    padding: .6rem .75rem;
    margin: .5rem 0 .5rem;
}

/* ---------------------------
   Lists / Links
---------------------------- */
ul {
    margin: .5rem 0 1rem 1.25rem;
}

a {
    color: var(--accent);
    text-decoration: none;
}

a:hover {
    text-decoration: underline;
}

/* ---------------------------
   Code Block (for blog outline)
---------------------------- */
.code-block {
    background: #0f172a;
    color: #e5e7eb;
    border-radius: 10px;
    padding: 1rem;
    overflow-x: auto;
    font-family: ui-monospace, SFMono-Regular, Menlo, Consolas, "Liberation Mono", monospace;
    font-size: .9rem;
    line-height: 1.5;
}

/* ---------------------------
   Helpers
---------------------------- */
.muted {
    color: var(--muted);
    font-size: .95rem;
}

/* ---------------------------
   Footer
---------------------------- */
.site-footer {
    text-align: center;
    margin: 2rem auto 0;
    padding: 1rem;
    background: var(--brand-900);
    color: #fff;
    font-size: .95rem;
    border-top-left-radius: 12px;
    border-top-right-radius: 12px;
}