:root {
    --bg: #EDF0F3;
    --surface: #FFFFFF;
    --ink: #1B2430;
    --ink-soft: #5A6675;
    --line: #D7DDE4;

    --easy: #157F6B;
    --easy-soft: #E1F0EC;
    --hard: #B26A00;
    --hard-soft: #F6ECD9;

    --radius: 14px;
    --shadow: 0 1px 2px rgba(27,36,48,.06), 0 8px 24px rgba(27,36,48,.08);
    --font: "Segoe UI", system-ui, -apple-system, Roboto, Helvetica, Arial, sans-serif;
}

* { box-sizing: border-box; }

html, body {
    margin: 0;
    min-height: 100%;
    background: var(--bg);
    color: var(--ink);
    font-family: var(--font);
    -webkit-font-smoothing: antialiased;
}

.stage {
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 40px 20px;
}

.screen { width: 100%; max-width: 920px; }
.hidden { display: none !important; }

h1 { font-size: 2rem; font-weight: 700; letter-spacing: -0.02em; margin: 0 0 8px; }
h2 { font-size: 1.5rem; font-weight: 700; letter-spacing: -0.015em; margin: 0 0 4px; }
.lede { color: var(--ink-soft); margin: 0; line-height: 1.5; max-width: 52ch; }
.msg { color: var(--ink-soft); min-width: 1.2em; margin: 14px 0 0; font-size: .95rem; }
.msg.error { color: #B23A2E; }

.primary, .ghost {
    font: inherit; font-weight: 600; cursor: pointer;
    border-radius: 10px; padding: 12px 22px; border: 1px solid transparent;
    transition: transform .08s ease, background .15s ease, border-color .15s ease;
}

.primary { background: var(--ink); color: #fff;}
.primary:hover:not(:disabled) { background: #0f1620; }
.primary:active:not(:disabled) { transform: translateY(1px); }
.primary:disabled { background: #c3cad3; cursor: not-allowed; }
.ghost { background: transparent; color: var(--ink); border-color: var(--line); }
.ghost:hover { border-color: var(--ink-soft); }
button:focus-visible { outline: 3px solid #4b93ff; outline-offset: 2px; }

.tag {
    display: inline-block; font-size: .78rem; font-weight: 700;
    padding: 3px 10px; border-radius: 999px; letter-spacing: .01em;
}
.tag--easy { background:var(--easy-soft); color: var(--easy); }
.tag--hard { background:var(--hard-soft); color: var(--hard); }

.top-bar {
    position: sticky; top: 0; z-index: 30;
    display: flex; align-items: center; justify-content: space-between;
    gap: 16px; padding: 14px 20px;
    background: var(--surface); border-bottom: 1px solid var(--line);
    box-shadow: 0 2px 8px rgba(27,36,48,.06);
}
.top-bar-count { font-weight: 600; font-size: .95rem; color: var(--ink-soft); }
.top-bar-home {
    font-weight: 600; font-size: .92rem; color: var(--ink);
    text-decoration: none; padding: 6px 4px;
}
.top-bar-home:hover { text-decoration: underline; }
.top-bar .primary { padding: 9px 16px; font-size: .92rem; }

.setup-head { margin-bottom: 20px; }
.random-draw {
    margin-top: 18px; border: 1px solid var(--line); border-radius: var(--radius);
    background: var(--surface); padding: 12px 16px;
}
.random-draw summary {
    cursor: pointer; font-weight: 600; font-size: .9rem; color: var(--ink-soft);
    list-style: none;
}
.random-draw summary::-webkit-details-marker { display: none; }
.random-draw summary::before { content: "▸ "; }
.random-draw[open] summary::before { content: "▾ "; }
.random-draw .steppers { display: grid; grid-template-columns: 1fr 1fr; gap: 12px; margin: 14px 0 14px; }
.random-draw .stepper { padding: 12px; }
.random-draw #start-btn { width: 100%; padding: 11px; font-size: .95rem; }

.stepper {
    background: var(--surface); border: 1px solid var(--line);
    border-radius: var(--radius); box-shadow: var(--shadow);
    padding: 20px; border-left: 4px solid var(--line);
}

.stepper--easy { border-left-color: var(--easy) }
.stepper--hard { border-left-color: var(--hard) }

.stepper-label { display: flex; align-items: center; gap: 10px; margin-bottom: 16px; }
.avail { color: var(--ink-soft); font-size: .88rem; }

.stepper-controls { display: flex; align-items: center; gap: 14px; }
.step-btn {
    width: 44px; height: 44px; border-radius: 10px; border: 1px solid var(--line);
    background: var(--bg); font-size: 1.4rem; line-height: 1; cursor: pointer;
    color: var(--ink); transition: background .12s ease;
}
.step-btn:hover:not(:disabled) { background: #e2e7ed; }
.step-btn:disabled { opacity: .4; cursor: not-allowed; }
.step-value {
    font-size: 1.8rem; font-weight: 700; min-width: 2ch; text-align: center;
    font-variant-numeric: tabular-nums;
}

.basket-summary {
    background: var(--surface); border: 1px solid var(--line);
    border-radius: var(--radius); box-shadow: var(--shadow);
    padding: 16px 18px; margin-bottom: 20px;
}
.basket-head { display: flex; align-items: center; justify-content: space-between; gap: 12px; }
.basket-title { font-weight: 700; font-size: .95rem; }
.basket-empty { color: var(--ink-soft); font-size: .88rem; margin: 10px 0 0; }
.basket-empty.hidden { display: none; }

.basket-list {
    list-style: none; margin: 12px 0 0; padding: 0;
    display: flex; flex-wrap: wrap; gap: 8px;
}
.basket-chip {
    display: flex; align-items: center; gap: 6px;
    border-radius: 999px; padding: 5px 6px 5px 12px; font-size: .85rem; font-weight: 600;
    background: var(--bg); border: 1px solid var(--line);
}
.basket-chip--easy { background: var(--easy-soft); color: var(--easy); }
.basket-chip--hard { background: var(--hard-soft); color: var(--hard); }
.basket-remove {
    font: inherit; line-height: 1; border: none; cursor: pointer;
    background: rgba(0,0,0,.08); color: inherit; border-radius: 50%;
    width: 18px; height: 18px; display: flex; align-items: center; justify-content: center;
}
.basket-remove:hover { background: rgba(0,0,0,.18); }

#start-btn { width: 100%; padding: 15px; font-size: 1.05rem; }

.browse-head {
    position: sticky; top: 0; z-index: 15;
    background: var(--bg);
    display: flex; align-items: flex-start; justify-content: space-between;
    gap: 16px; margin-bottom: 20px; padding: 12px 0; flex-wrap: wrap;
    border-bottom: 1px solid var(--line);
}

.browse-grid {
    display: grid; grid-template-columns: repeat(3, 1fr);
    gap: 16px;
}

.browse-card {
    position: relative; text-align: left; cursor: pointer;
    background: var(--surface); border: 1px solid var(--line);
    border-radius: var(--radius); box-shadow: var(--shadow);
    padding: 0; overflow: hidden; font: inherit;
    transition: border-color .12s ease, transform .08s ease;
}
.browse-card:hover { border-color: var(--ink-soft); }
.browse-card:active { transform: translateY(1px); }
.browse-card.selected { border-color: var(--ink); border-width: 2px; }

.browse-card-img {
    height: 130px; display: flex; align-items: center; justify-content: center;
    padding: 10px; overflow: hidden;
}
.browse-card-img img { max-width: 100%; max-height: 100%; object-fit: contain; }

.browse-card-foot {
    display: flex; align-items: center; justify-content: space-between; gap: 8px;
    padding: 10px 12px; border-top: 1px solid var(--line);
}
.browse-card-foot .name { font-weight: 600; font-size: .88rem; }

.browse-check {
    position: absolute; top: 10px; right: 10px; z-index: 1;
    width: 24px; height: 24px; border-radius: 50%;
    background: var(--surface); border: 1px solid var(--line); color: transparent;
    display: flex; align-items: center; justify-content: center; font-size: .8rem;
    transition: background .12s ease, color .12s ease, border-color .12s ease;
}
.browse-card.selected .browse-check {
    background: var(--ink); border-color: var(--ink); color: #fff;
}

#screen-confirm { max-width: 560px; text-align: center; padding-bottom: 104px; }
.confirm-progress { color: var(--ink-soft); font-size: .9rem; margin-bottom: 16px;
    font-variant-numeric: tabular-nums; }

.review-card{
    position: relative; background: var(--surface); border: 1px solid var(--line);
    border-radius: var(--radius); box-shadow: var(--shadow); padding: 18px;
    margin-bottom: 22px;
}

.review-card .tag { position: absolute; top: 16px; left: 16px; }
.review-image-wrap {
    display: flex; align-items: center; justify-content: center;
    min-height: 300px; overflow: hidden; border-radius: 8px;
}
.review-image-wrap img { max-width: 100%; max-height: 46vh; object-fit: contain; display: block; }
.review-name { font-weight: 700; font-size: 1.05rem; margin: 14px 0 0; }

.confirm-question { font-size: 1.15rem; font-weight: 600; margin: 0 0 18px; }
.browse-link { display: block; margin: 0 auto 12px; }

.confirm-actions {
    position: fixed; left: 50%; bottom: 0; transform: translateX(-50%);
    width: 100%; max-width: 560px; z-index: 20;
    display: flex; gap: 12px; justify-content: center;
    padding: 16px 20px calc(16px + env(safe-area-inset-bottom, 0px));
    background: var(--surface); border: 1px solid var(--line); border-bottom: none;
    border-radius: var(--radius) var(--radius) 0 0;
    box-shadow: 0 -8px 24px rgba(27,36,48,.10);
}
.confirm-actions button { min-width: 150px; }

.study-head-actions { display: flex; gap: 10px; flex-wrap: wrap; }

.study-head { 
    display: flex; align-items: flex-end; justify-content: space-between;
    gap: 16px; margin-bottom: 24px; flex-wrap: wrap;
}

.study-grid { 
    display: grid; grid-template-columns: repeat(auto-fill, minmax(230px, 1fr));
    gap: 18px;
}

.card {
    perspective: 1200px; height: 280px; cursor: pointer;
    background: none; border: none; padding: 0; font: inherit;
}

.card-inner {
    position: relative; width: 100%; height: 100%;
    transform-style: preserve-3d;
    transition: transform .5s cubic-bezier(.2,.7,.2,1);
}
.card.flipped .card-inner { transform: rotateY(180deg); }

.card-face {
    position: absolute; inset: 0; backface-visibility: hidden;
    border-radius: var(--radius); border: 1px solid var(--line);
    background: var(--surface); box-shadow: var(--shadow); overflow: hidden;
}

.card-back {
    transform: rotateY(180deg);
    display: flex; flex-direction: column; overflow: hidden;
}
.card-back ul { flex: 1; overflow-y: auto; margin: 0; padding: 10px 14px; }

.recipe-link {
    display: inline-block; margin: 0 14px 12px; margin-top: auto;
    font-size: .85rem; font-weight: 600; color: var(--ink);
    text-decoration: underline; cursor: pointer; flex: 0 0 auto;
}

.card-front { display: flex; flex-direction: column; }
.card-front .spine { height: 5px; flex: 0 0 auto; }
.card--easy .spine { background: var(--easy); }
.card--hard .spine { background: var(--hard); }
.card-front .img {
    flex: 1; display: flex; align-items: center; justify-content: center;
    padding: 14px; overflow: hidden;
}
.card-front .img img { max-width: 100%; max-height: 100%; object-fit: contain; }
.card-front .foot {
    display: flex; align-items: center; justify-content: space-between;
    padding: 10px 14px; border-top: 1px solid var(--line);
}
.card-front .foot .hint { color: var(--ink-soft); font-size: .8rem; }

.card-back .back-head {
    padding: 10px 14px; border-bottom: 1px solid var(--line);
    display: flex; align-items: center; justify-content: space-between; flex: 0 0 auto;
}
.card-back .back-head .name { font-weight: 700; font-size: .95rem; }
.card--easy .card-back { border-top: none; }

@media (max-width: 560px) {
    h1 { font-size: 1.6rem; }
    .steppers { grid-template-columns: 1fr; }
    .confirm-actions { flex-direction: column-reverse; padding: 14px 16px calc(14px + env(safe-area-inset-bottom, 0px)); }
    .confirm-actions button { width: 100%; }
    #screen-confirm { padding-bottom: 148px; }
    .browse-grid { grid-template-columns: 1fr; }
    .basket-head { flex-direction: column; align-items: flex-start; }
}

@media (max-width: 760px) and (min-width: 561px) {
    .browse-grid { grid-template-columns: repeat(2, 1fr); }
}

@media (prefers-reduced-motion: reduce) {
    .card-inner { transition: none; }
    .primary, .ghost { transition: none; }
}

.modal-overlay {
    position: fixed; inset: 0; z-index: 100;
    background: rgba(15, 22, 32, .55);
    display: flex; align-items: center; justify-content: center;
    padding: 20px;
}
.modal-overlay.hidden { display: none; }

.modal-card {
    background: var(--surface); border-radius: var(--radius);
    box-shadow: var(--shadow); max-width: 480px; width: 100%;
    max-height: 80vh; overflow-y: auto;
    padding: 20px;
}
.modal-head {
    display: flex; align-items: flex-start; justify-content: space-between;
    margin-bottom: 14px; gap: 12px;
}
.modal-title { font-weight: 700; font-size: 1.1rem; }
.modal-close {
    background: none; border: none; font-size: 1.4rem; line-height: 1;
    cursor: pointer; color: var(--ink-soft); padding: 2px 8px; border-radius: 8px;
    flex: 0 0 auto;
}
.modal-close:hover { background: var(--bg); }
.modal-body { white-space: pre-line; line-height: 1.6; font-size: .95rem; }