/* pianoforbeginners.com — course app design system */
:root {
  --ivory: #f7f7f9;
  --paper: #ececef;
  --ink: #16181f;
  --ink-soft: #4c4f58;
  --ink-faint: #7d818c;
  --accent: #f61a30;
  --accent-deep: #d31128;
  --accent-soft: #fde5e8;
  --gold: #b08a3e;
  --green: #5f806c;
  --green-soft: #e7eee6;
  --dark: #201617;
  --dark-soft: #2b1e1f;
  --on-dark: #f4f5f7;
  --on-dark-faint: #9b9fa8;
  --key-white: #fdfdfd;
  --key-black: #16181f;
  --key-active: #e9b87a;
  --key-target: #cfe3d5;
  --radius: 16px;
  --shadow: 0 2px 10px rgba(2,8,21,.06), 0 16px 40px rgba(2,8,21,.09);
}
* { margin: 0; padding: 0; box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  font-family: 'Inter', -apple-system, sans-serif;
  background: var(--ivory);
  color: var(--ink);
  line-height: 1.6;
  font-size: 16.5px;
  -webkit-font-smoothing: antialiased;
}
h1, h2, h3, .serif { font-family: 'Fraunces', Georgia, serif; font-weight: 600; line-height: 1.15; }
.wrap { max-width: 880px; margin: 0 auto; padding: 0 20px; }

/* ---------- Top bar ---------- */
.topbar {
  position: sticky; top: 0; z-index: 40;
  background: rgba(250,247,241,.97);
  border-bottom: 1px solid rgba(28,26,23,.08);
}
.topbar-inner { display: flex; align-items: center; justify-content: space-between; height: 58px; max-width: 1080px; margin: 0 auto; padding: 0 20px; }
.logo { font-family: 'Fraunces', serif; font-weight: 700; font-size: 17px; text-decoration: none; color: var(--ink); }
.logo span { color: var(--accent); }
.topbar .crumbs { font-size: 13.5px; color: var(--ink-faint); }
.topbar a.back { font-size: 14px; font-weight: 600; color: var(--accent); text-decoration: none; }

/* ---------- Buttons ---------- */
.btn {
  font: inherit; font-size: 15.5px; font-weight: 600;
  background: var(--accent); color: #fff;
  border: none; border-radius: 999px;
  padding: 12px 26px; cursor: pointer;
  transition: background .15s, transform .1s, opacity .15s;
  text-decoration: none; display: inline-block;
}
.btn:hover { background: var(--accent-deep); }
.btn:active { transform: scale(.98); }
.btn.ghost { background: transparent; color: var(--ink); border: 1.5px solid rgba(28,26,23,.2); }
.btn.ghost:hover { border-color: var(--accent); color: var(--accent); }
.btn:disabled { opacity: .45; cursor: default; }

/* ---------- Course home ---------- */
.course-head { padding: 48px 0 8px; }
.course-head h1 { font-size: clamp(28px, 4.5vw, 40px); margin-bottom: 10px; }
.course-head p { color: var(--ink-soft); max-width: 560px; }
.progress-strip {
  display: flex; align-items: center; gap: 14px;
  background: #fff; border: 1px solid rgba(28,26,23,.09);
  border-radius: var(--radius); padding: 16px 20px; margin: 26px 0 8px;
  box-shadow: var(--shadow);
}
.progress-bar { flex: 1; height: 8px; background: var(--paper); border-radius: 99px; overflow: hidden; }
.progress-bar i { display: block; height: 100%; background: var(--accent); border-radius: 99px; transition: width .4s; }
.progress-strip .pct { font-size: 13.5px; font-weight: 600; color: var(--ink-soft); white-space: nowrap; }

.module { margin: 34px 0; }
.module-head { display: flex; align-items: baseline; justify-content: space-between; margin-bottom: 14px; }
.module-head h2 { font-size: 21px; }
.module-head .days { font-size: 12.5px; font-weight: 600; letter-spacing: .1em; text-transform: uppercase; color: var(--accent); }
.module.locked .module-head h2 { color: var(--ink-faint); }
.lesson-list { display: flex; flex-direction: column; gap: 10px; }
.lesson-card {
  display: flex; align-items: center; gap: 16px;
  background: #fff; border: 1px solid rgba(28,26,23,.09);
  border-radius: var(--radius); padding: 16px 20px;
  text-decoration: none; color: var(--ink);
  transition: border-color .15s, transform .12s;
}
a.lesson-card:hover { border-color: var(--accent); transform: translateX(3px); }
.lesson-card .dot {
  width: 34px; height: 34px; border-radius: 50%; flex-shrink: 0;
  display: flex; align-items: center; justify-content: center;
  font-size: 14px; font-weight: 700;
  background: var(--paper); color: var(--ink-faint);
}
.lesson-card.done .dot { background: var(--green-soft); color: var(--green); }
.lesson-card .meta { flex: 1; min-width: 0; }
.lesson-card h3 { font-size: 16.5px; font-family: 'Inter', sans-serif; font-weight: 600; }
.lesson-card p { font-size: 13.5px; color: var(--ink-faint); }
.lesson-card .tag {
  font-size: 11px; font-weight: 700; letter-spacing: .08em; text-transform: uppercase;
  padding: 4px 10px; border-radius: 4px; white-space: nowrap;
}
.tag.free { background: var(--green-soft); color: var(--green); }
.tag.locked { background: var(--paper); color: var(--ink-faint); }
.module.locked .lesson-card { opacity: .65; }

.unlock-box {
  margin: 44px 0 60px;
  background: var(--dark); color: var(--on-dark);
  border-radius: 18px; padding: 30px 30px;
  display: flex; align-items: center; gap: 24px; flex-wrap: wrap;
}
.unlock-box .serif { font-size: 20px; }
.unlock-box p { font-size: 14px; color: var(--on-dark-faint); }
.unlock-box form { display: flex; gap: 10px; margin-left: auto; }
.unlock-box input {
  font: inherit; font-size: 15px; padding: 10px 16px;
  border-radius: 999px; border: 1.5px solid rgba(239,233,221,.25);
  background: var(--dark-soft); color: var(--on-dark); outline: none;
}
.unlock-box input:focus { border-color: var(--key-active); }

/* ---------- Lesson page ---------- */
.lesson-shell { padding-bottom: 300px; } /* room for piano dock */
.lesson-head { padding: 36px 0 6px; }
.lesson-head .kicker { font-size: 12.5px; font-weight: 700; letter-spacing: .12em; text-transform: uppercase; color: var(--accent); }
.lesson-head h1 { font-size: clamp(26px, 4vw, 36px); margin: 6px 0 4px; }
.lesson-head .sub { color: var(--ink-soft); font-size: 15.5px; }
.steps { display: flex; flex-direction: column; gap: 18px; margin-top: 26px; }
.step-card {
  background: #fff; border: 1px solid rgba(28,26,23,.09);
  border-radius: 18px; padding: 28px 30px;
  box-shadow: var(--shadow);
  animation: rise .35s ease both;
}
@keyframes rise { from { opacity: 0; transform: translateY(14px); } to { opacity: 1; transform: none; } }
.step-card .kicker {
  font-size: 11.5px; font-weight: 700; letter-spacing: .1em; text-transform: uppercase;
  color: var(--accent); margin-bottom: 10px; display: block;
}
.step-card h2 { font-size: 22px; margin-bottom: 12px; }
.step-card p { color: var(--ink-soft); font-size: 16px; margin-bottom: 12px; }
.step-card p:last-of-type { margin-bottom: 0; }
.step-card strong { color: var(--ink); }
.step-card .actions { margin-top: 20px; display: flex; gap: 12px; align-items: center; flex-wrap: wrap; }

/* task states */
.task-status {
  display: flex; align-items: center; gap: 10px;
  margin-top: 18px; padding: 14px 18px;
  border-radius: 12px; font-size: 15px; font-weight: 600;
  background: var(--accent-soft); color: var(--accent-deep);
}
.task-status.ok { background: var(--green-soft); color: var(--green); }
.step-card.completed { border-color: rgba(61,122,74,.4); }
.step-card.completed .task-status { background: var(--green-soft); color: var(--green); }

/* chord diagram */
.chord-diagram { display: flex; gap: 20px; align-items: center; margin: 18px 0; flex-wrap: wrap; }
.chord-name {
  font-family: 'Fraunces', serif; font-size: 44px; font-weight: 700;
  background: var(--paper); border-radius: 14px;
  padding: 10px 26px;
}
.chord-notes { font-size: 15px; color: var(--ink-soft); }
.chord-notes b { font-size: 18px; color: var(--ink); letter-spacing: .06em; }

/* quiz */
.quiz-opts { display: flex; flex-direction: column; gap: 10px; margin-top: 14px; }
.quiz-opt {
  font: inherit; text-align: left; font-size: 15.5px;
  background: var(--ivory); border: 1.5px solid rgba(28,26,23,.14);
  border-radius: 12px; padding: 13px 18px; cursor: pointer;
  transition: all .15s;
}
.quiz-opt:hover { border-color: var(--accent); }
.quiz-opt.right { background: var(--green-soft); border-color: var(--green); font-weight: 600; }
.quiz-opt.wrong { background: var(--accent-soft); border-color: var(--accent); opacity: .7; }

/* video slot */
.video-slot {
  border: 2px dashed rgba(28,26,23,.18);
  border-radius: 14px; padding: 28px;
  text-align: center; color: var(--ink-faint); font-size: 14px;
  margin-top: 14px;
}
.video-slot.has-video { border: none; padding: 0; }
.video-slot iframe { width: 100%; aspect-ratio: 16/9; border: none; border-radius: 14px; }

/* looper */
.looper { margin-top: 18px; }
.looper-chords { display: flex; gap: 10px; margin-bottom: 16px; }
.looper-chord {
  flex: 1; text-align: center;
  font-family: 'Fraunces', serif; font-size: 26px; font-weight: 700;
  background: var(--paper); border-radius: 12px; padding: 14px 0;
  border: 2px solid transparent;
  transition: all .12s;
}
.looper-chord.now { background: var(--accent-soft); border-color: var(--accent); transform: scale(1.04); }
.looper-ctrl { display: flex; gap: 12px; align-items: center; }
.looper-ctrl .bpm { font-size: 13.5px; color: var(--ink-faint); }

/* complete banner */
.complete-card {
  background: var(--dark); color: var(--on-dark);
  border-radius: 18px; padding: 40px 34px;
  text-align: center;
}
.complete-card h2 { font-size: 30px; margin-bottom: 10px; }
.complete-card p { color: var(--on-dark-faint); margin-bottom: 20px; }
.complete-card .won {
  font-family: 'Fraunces', serif; font-size: 19px; color: var(--key-active);
  margin-bottom: 10px;
}
.complete-card .won em { font-style: italic; }
.complete-actions { display: flex; gap: 12px; justify-content: center; flex-wrap: wrap; }

/* unlocks line on course home */
.unlocks {
  margin: 14px 2px 0;
  font-size: 15px; color: var(--ink-soft);
}
.unlocks .serif { color: var(--accent); }

/* confetti */
.confetti { position: fixed; inset: 0; pointer-events: none; z-index: 200; overflow: hidden; }
.confetti i {
  position: absolute; top: -20px; display: block;
  animation: confetti-fall linear forwards;
}
@keyframes confetti-fall {
  0%   { transform: translateY(-20px) rotate(0deg); opacity: 1; }
  85%  { opacity: 1; }
  100% { transform: translateY(105vh) rotate(560deg); opacity: 0; }
}

/* ---------- Piano dock ---------- */
.piano-dock {
  position: fixed; left: 0; right: 0; bottom: 0; z-index: 50;
  background: #fff;
  border-top: 1px solid rgba(28,26,23,.12);
  box-shadow: 0 -8px 32px rgba(28,26,23,.1);
  padding: 12px 16px 14px;
}
.piano-dock-inner { max-width: 880px; margin: 0 auto; }
.dock-info { display: flex; justify-content: space-between; align-items: center; margin-bottom: 8px; font-size: 12.5px; color: var(--ink-faint); }
.dock-info .midi-status { display: flex; align-items: center; gap: 6px; }
.midi-dot { width: 7px; height: 7px; border-radius: 50%; background: var(--ink-faint); }
.midi-dot.on { background: var(--green); }
.sound-toggle {
  font: inherit; font-size: 12px; font-weight: 600;
  color: var(--ink-soft); background: var(--paper);
  border: 1px solid rgba(28,26,23,.14); border-radius: 999px;
  padding: 3px 12px; cursor: pointer;
  transition: all .15s;
}
.sound-toggle:hover { border-color: var(--accent); color: var(--accent); }
.keys {
  display: flex; position: relative;
  height: 130px;
  border-radius: 8px; overflow: hidden;
  border: 1px solid rgba(28,26,23,.15);
  user-select: none; touch-action: none;
}
.wk {
  flex: 1; background: var(--key-white);
  border-right: 1px solid rgba(28,26,23,.14);
  position: relative; cursor: pointer;
  transition: background .1s;
}
.wk:last-child { border-right: none; }
.wk.lit { background: var(--key-active); }
.wk.target { background: var(--key-target); }
.wk.lit.target { background: var(--key-active); }
.wk .lbl { position: absolute; bottom: 6px; left: 50%; transform: translateX(-50%); font-size: 10.5px; font-weight: 600; color: var(--ink-faint); }
.wk .qwerty { position: absolute; bottom: 22px; left: 50%; transform: translateX(-50%); font-size: 9.5px; color: rgba(28,26,23,.28); font-weight: 600; }
.bk {
  position: absolute; top: 0; width: 4.2%; height: 58%;
  background: var(--key-black);
  border-radius: 0 0 4px 4px;
  z-index: 2; cursor: pointer;
  transition: background .1s;
}
.bk.lit { background: var(--gold); }
.bk.target { background: #6f8f7a; }

@media (max-width: 700px) {
  .keys { height: 104px; }
  .lesson-shell { padding-bottom: 240px; }
  .step-card { padding: 22px 20px; }
  .unlock-box form { margin-left: 0; width: 100%; }
  .unlock-box input { flex: 1; min-width: 0; }
}