/* [2026-10-04 학생 메뉴 리디자인 · C안 «조각»] 로그인 화면이 조각 홈과 같은 4열 격자(단위 80 · 간격 10 · 여백 14).
           특대 = 오늘의 한 줄, 큰 조각 = 로그인 카드, 2×2 = 오늘의 국어 · 디데이, 소 = 로그인하면 열리는 조각 미리보기.
           폼·id·JS 는 그대로. 밝은 모드 하나. */
        *, *::before, *::after { box-sizing: border-box; }
        * { margin: 0; }
        :root {
            --brand: #2563eb; --brand-strong: #1d4ed8; --brand-soft: #eaf0fe;
            --ink: #0f172a; --ink-2: #334155; --muted: #64748b; --faint: #94a3b8;
            --line: #e5e8ee; --surface: #ffffff; --canvas: #f6f7f9; --press: #f1f5f9;
            --danger: #b91c1c; --danger-bg: #fef2f2; --warn: #92400e; --warn-bg: #fffbeb;
            --u: 80px; --g: 10px;
        }
        html { min-height: 100%; background: var(--canvas); }
        body {
            min-width: 320px; min-height: 100vh; min-height: 100dvh; color: var(--ink); background: var(--canvas);
            font-family: 'Pretendard Variable', 'Pretendard', -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Malgun Gothic', sans-serif;
            -webkit-font-smoothing: antialiased; word-break: keep-all; -webkit-tap-highlight-color: transparent;
        }
        .app-screen { display: flex; flex-direction: column; align-items: center; min-height: 100dvh; }

        /* 상단 바 */
        .hero { width: 100%; height: calc(56px + env(safe-area-inset-top)); padding: env(safe-area-inset-top) 14px 0; display: flex; flex-direction: row; align-items: center; gap: 8px; background: var(--surface); border-bottom: 1px solid var(--line); }
        .brand-mark { width: 30px; height: 30px; display: grid; place-items: center; border-radius: 9px; background: var(--brand); color: #fff; font-size: 14px; font-weight: 800; flex-shrink: 0; }
        .hero-title { font-size: 16px; font-weight: 800; letter-spacing: -.01em; }
        .hero-sub { margin-left: auto; font-size: 12px; color: var(--muted); }
        .hero-kicker, .hero-points, .eyebrow, .reading3-callout, .field-icon { display: none; }

        /* 격자: 띠 안의 조각과 로그인 카드가 같은 격자에 놓인다 */
        .dd-strip { display: contents; }
        .login-card { display: contents; }
        .app-screen > .dd-strip + .login-card { display: contents; }
        .app-screen::after { content: ''; order: 99; height: 16px; }
        .dd-hero, .card-inner, .kpair, .dd-card, .pv-list { width: calc(100% - 28px); max-width: 532px; }
        .dd-hero { order: 1; margin-top: 12px; }
        .card-inner { order: 2; margin-top: var(--g); }
        .kpair { order: 3; margin-top: var(--g); display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: var(--g); }
        .dd-card { order: 4; margin-top: var(--g); }
        .pv-list { order: 5; margin-top: var(--g); }

        /* 특대: 오늘의 한 줄 */
        .dd-hero { min-height: 124px; display: flex; flex-direction: column; justify-content: space-between; gap: 10px; padding: 14px 16px; border-radius: 18px; background: var(--brand-strong); color: #fff; }
        .dd-hero-top { display: flex; align-items: center; justify-content: space-between; gap: 8px; }
        .dd-hero-k { font-size: 12px; font-weight: 700; letter-spacing: .06em; opacity: .85; white-space: nowrap; }
        .dd-hero-pill { font-size: 12px; font-weight: 700; padding: 3px 9px; border-radius: 999px; background: rgba(255,255,255,.18); white-space: nowrap; }
        .dd-hero-main { display: flex; flex-direction: column; gap: 3px; }
        .dd-hero-main strong { font-size: 19px; line-height: 1.3; letter-spacing: -.01em; }
        .dd-hero-main span { font-size: 12.5px; opacity: .85; }

        /* 큰 조각: 로그인 카드 */
        .card-inner { background: var(--surface); border: 1px solid var(--line); border-radius: 18px; padding: 18px 16px 16px; box-shadow: 0 14px 40px -26px rgba(37,99,235,.5); }
        .card-heading { font-size: 20px; font-weight: 800; letter-spacing: -.02em; line-height: 1.25; }
        .card-sub { margin: 4px 0 14px; font-size: 13px; line-height: 1.5; color: var(--muted); }
        .notice-box, .error-box { display: flex; align-items: flex-start; gap: 8px; margin: -4px 0 12px; padding: 10px 12px; border-radius: 12px; font-size: 13px; line-height: 1.5; font-weight: 600; }
        .notice-box { background: var(--warn-bg); color: var(--warn); }
        .error-box { background: var(--danger-bg); color: var(--danger); }
        .error-box i, .notice-box i { flex-shrink: 0; margin-top: 2px; }
        .field-group { margin-bottom: 12px; }
        .field-label { display: block; margin-bottom: 6px; font-size: 13px; font-weight: 700; color: var(--ink-2); }
        .field-wrap { position: relative; }
        .field-input { width: 100%; height: 50px; padding: 0 14px; border: 1px solid var(--line); border-radius: 12px; background: var(--surface); color: var(--ink); font: inherit; font-size: 16px; font-weight: 600; outline: none; appearance: none; transition: border-color .12s ease, box-shadow .12s ease; }
        .field-input.has-toggle { padding-right: 52px; }
        .field-input::placeholder { color: var(--faint); font-weight: 500; }
        .field-input:focus { border-color: var(--brand); box-shadow: 0 0 0 3px rgba(37,99,235,.12); }
        .field-input[aria-invalid="true"] { border-color: #ef4444; box-shadow: 0 0 0 3px rgba(239,68,68,.1); }
        #student_id { font-size: 19px; font-weight: 800; letter-spacing: .24em; font-variant-numeric: tabular-nums; }
        #student_id::placeholder { font-size: 16px; letter-spacing: .06em; font-weight: 500; }
        .field-help { margin-top: 5px; font-size: 12px; line-height: 1.45; color: var(--muted); }
        .password-toggle { position: absolute; right: 5px; top: 50%; transform: translateY(-50%); width: 44px; height: 40px; display: grid; place-items: center; border: 0; border-radius: 10px; background: transparent; color: var(--muted); font-size: 17px; cursor: pointer; }
        .password-toggle:active { background: var(--press); }
        .remember-row { display: flex; align-items: flex-start; gap: 10px; margin: 2px 0 14px; cursor: pointer; }
        .remember-row input { width: 20px; height: 20px; margin: 1px 0 0; flex-shrink: 0; accent-color: var(--brand); cursor: pointer; }
        .remember-text { display: flex; flex-direction: column; gap: 2px; font-size: 14px; font-weight: 600; color: var(--ink); }
        .remember-hint { font-size: 12px; font-weight: 500; line-height: 1.45; color: var(--muted); }
        .btn-login, .btn-confirm { width: 100%; height: 52px; border: 0; border-radius: 14px; background: var(--brand); color: #fff; font: inherit; font-size: 16px; font-weight: 800; letter-spacing: -.01em; cursor: pointer; transition: transform .08s ease, background .12s ease; }
        .btn-login:hover, .btn-confirm:hover { background: var(--brand-strong); }
        .btn-login:active, .btn-confirm:active { transform: scale(.985); }
        .btn-login:disabled { cursor: wait; opacity: .7; }
        :focus-visible { outline: 3px solid #93c5fd; outline-offset: 2px; }
        .session-card { padding: 16px; border: 1px solid var(--line); border-radius: 14px; background: var(--canvas); }
        .session-icon { width: 40px; height: 40px; display: grid; place-items: center; margin-bottom: 10px; border-radius: 12px; color: var(--brand); background: var(--brand-soft); font-size: 19px; }
        .session-title { font-size: 17px; font-weight: 800; letter-spacing: -.01em; }
        .session-copy { margin: 6px 0 14px; color: var(--muted); font-size: 14px; line-height: 1.55; }
        .session-cancel { display: block; margin-top: 10px; min-height: 44px; line-height: 44px; text-align: center; color: var(--muted); font-size: 14px; font-weight: 700; text-decoration: none; }
        .web-link { margin-top: 14px; text-align: center; color: var(--muted); font-size: 12.5px; line-height: 1.5; }
        .web-link a { display: inline-block; margin-left: 6px; min-height: 24px; color: var(--brand); font-weight: 700; text-decoration: none; }
        .sr-only { position: absolute; width: 1px; height: 1px; padding: 0; margin: -1px; overflow: hidden; clip: rect(0,0,0,0); white-space: nowrap; border: 0; }

        /* 2×2 두 개: 성어 · 맞춤법 */
        .kcard { min-height: calc(var(--u) * 2 + var(--g)); display: flex; flex-direction: column; padding: 11px 12px 10px; border-radius: 16px; background: var(--surface); border: 1px solid var(--line); min-width: 0; }
        .kcard-top { display: flex; align-items: center; gap: 2px; }
        .kcard-cat { display: inline-flex; align-items: center; height: 24px; padding: 0 9px; border-radius: 999px; font-size: 11.5px; font-weight: 800; white-space: nowrap; margin-right: auto; }
        .kcard-idiom .kcard-cat { background: #efeefa; color: #5f5aa6; }
        .kcard-spell .kcard-cat { background: #e7f5f3; color: #0f766e; }
        .kcard-concept .kcard-cat { background: #eaf0fe; color: #1d4ed8; }
        .kcard-concept { grid-column: 1 / -1; min-height: 0; }
        .kcard-concept .kcard-meaning { -webkit-line-clamp: 2; }
        .kcard-quiz, .kcard-btn { width: 30px; height: 30px; display: grid; place-items: center; border: 0; border-radius: 9px; background: transparent; color: var(--muted); font: inherit; font-size: 14px; cursor: pointer; }
        .kcard-quiz:active, .kcard-btn:active { background: var(--press); }
        .kcard-quiz[aria-pressed="true"] { background: var(--ink); color: #fff; }
        .kcard-word { margin-top: 8px; font-size: 16.5px; font-weight: 800; letter-spacing: -.01em; line-height: 1.25; }
        .kcard-meaning { position: relative; display: block; width: 100%; margin-top: 5px; padding: 0; border: 0; background: transparent; text-align: left; font: inherit; font-size: 12.5px; line-height: 1.45; color: var(--ink-2); cursor: default; display: -webkit-box; -webkit-line-clamp: 3; -webkit-box-orient: vertical; overflow: hidden; }
        .kcard.quiz .kcard-meaning { cursor: pointer; }
        .kcard.quiz.hidden .kcard-meaning { color: transparent; text-shadow: 0 0 10px rgba(15,23,42,.35); user-select: none; }
        .kcard.quiz.hidden .kcard-meaning::after { content: '탭하여 뜻 확인'; position: absolute; left: 0; top: 0; color: var(--brand); text-shadow: none; font-weight: 700; }
        .kcard-foot { display: flex; justify-content: space-between; align-items: baseline; gap: 8px; margin-top: auto; padding-top: 6px; border-top: 1px solid var(--line); min-width: 0; }
        .kcard-tip { font-size: 11px; line-height: 1.4; color: var(--muted); white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
        .kcard-count { flex-shrink: 0; font-size: 11px; font-weight: 700; color: var(--faint); font-variant-numeric: tabular-nums; }
        .kcard.swap .kcard-word, .kcard.swap .kcard-meaning, .kcard.swap .kcard-foot { animation: kfade .28s ease; }
        @keyframes kfade { from { opacity: 0; transform: translateY(3px); } to { opacity: 1; transform: none; } }

        /* 2×2: 디데이 */
        .dd-card { display: flex; flex-direction: column; gap: 8px; padding: 12px 14px; border-radius: 16px; background: var(--surface); border: 1px solid var(--line); }
        .dd-card-k { font-size: 11.5px; font-weight: 800; color: var(--muted); letter-spacing: .04em; }
        .dd-list { list-style: none; margin: 0; padding: 0; display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 6px; }
        .dd-card { min-height: 0; }
        .dd-chip { display: flex; align-items: center; justify-content: space-between; gap: 6px; min-height: 36px; padding: 0 10px; border-radius: 10px; background: var(--canvas); font-size: 12.5px; font-weight: 600; color: var(--ink-2); }
        .dd-chip span { white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
        .dd-chip b { font-weight: 800; color: var(--brand); font-variant-numeric: tabular-nums; flex-shrink: 0; }
        .dd-chip.hot b { color: #b91c1c; }
        .dd-chip.dd-suneung { grid-column: span 2; min-height: 44px; background: var(--brand); color: #fff; font-size: 13.5px; }
        .dd-chip.dd-suneung b, .dd-chip.dd-suneung.hot b { color: #fff; font-size: 17px; }

        /* 소: 미리보기 조각 */
        .pv-list { list-style: none; margin: 0; padding: 0; display: grid; grid-template-columns: repeat(4, minmax(0, 1fr)); gap: var(--g); }
        .pv-tile { height: var(--u); display: flex; flex-direction: column; justify-content: space-between; padding: 10px; border-radius: 16px; background: var(--surface); border: 1px solid var(--line); }
        .pv-ic { display: grid; place-items: center; width: 28px; height: 28px; border-radius: 10px; background: var(--soft); color: var(--c); }
        .pv-tile strong { font-size: 12px; line-height: 15px; letter-spacing: -.01em; display: -webkit-box; -webkit-line-clamp: 2; -webkit-box-orient: vertical; overflow: hidden; }

        /* 폰에서 키보드가 올라오면 한 줄 조각을 줄인다 */
        @media (max-width: 899px) {
            .app-screen:focus-within .dd-hero { min-height: 0; padding: 10px 14px; }
            .app-screen:focus-within .dd-hero-main strong { font-size: 14px; }
            .app-screen:focus-within .dd-hero-main span { display: none; }
        }

        /* 넓은 화면: 6열 조각 격자, 로그인 카드는 오른쪽 큰 조각 */
        @media (min-width: 900px) {
            :root { --u: 112px; --g: 14px; }
            .app-screen { align-items: stretch; }
            .hero { height: 64px; padding: 0 32px; gap: 10px; }
            .brand-mark { width: 34px; height: 34px; border-radius: 10px; font-size: 15px; }
            .hero-title { font-size: 18px; }
            .hero-sub { font-size: 13px; }
            .dd-strip, .login-card { display: contents; }
            .app-screen > .hero { order: 0; }
            .dd-hero, .card-inner, .kpair, .dd-card, .pv-list { width: auto; max-width: none; margin: 0; }
            .app-screen::after { display: none; }
            /* 격자 컨테이너: hero 를 뺀 나머지를 grid 로 — body 단계에서 grid 를 쓸 수 없어 app-screen 에 grid, hero 는 6열 */
            .app-screen { display: grid; grid-template-columns: repeat(6, minmax(0, 1fr)); grid-auto-rows: minmax(var(--u), auto); gap: var(--g); width: min(1180px, calc(100% - 64px)); margin: 0 auto; padding: 22px 0 40px; min-height: 0; }
            .hero { grid-column: 1 / -1; order: 0; height: 64px; border: 1px solid var(--line); border-radius: 18px; padding: 0 20px; }
            .dd-hero { grid-column: span 4; order: 1; min-height: 0; border-radius: 20px; padding: 18px 24px; }
            .dd-hero-main strong { font-size: 24px; }
            .card-inner { grid-column: span 2; grid-row: span 4; order: 2; padding: 24px 22px 20px; display: flex; flex-direction: column; }
            .kpair { grid-column: span 4; grid-row: span 2; order: 3; grid-template-columns: repeat(3, minmax(0, 1fr)); }
            .kcard-concept { grid-column: auto; min-height: calc(var(--u) * 2 + var(--g)); }
            .kcard-concept .kcard-meaning { -webkit-line-clamp: 4; }
            .kcard { min-height: 0; padding: 14px 16px 12px; }
            .kcard-word { font-size: 17px; }
            .kcard-meaning { font-size: 13.5px; }
            .dd-card { grid-column: span 4; order: 4; }
            .dd-list { grid-template-columns: repeat(4, minmax(0, 1fr)); }
            .dd-chip.dd-suneung { grid-column: span 1; min-height: 36px; font-size: 12.5px; }
            .dd-chip.dd-suneung b { font-size: 14px; }
            .pv-list { grid-column: span 4; order: 5; }
            .pv-tile { height: var(--u); padding: 14px; }
            .pv-ic { width: 34px; height: 34px; }
            .pv-tile strong { font-size: 14px; line-height: 18px; }
            .card-heading { font-size: 24px; }
            .web-link { margin-top: auto; padding-top: 14px; }
        }
        @media (prefers-reduced-motion: reduce) {
            *, *::before, *::after { scroll-behavior: auto !important; transition-duration: .01ms !important; animation-duration: .01ms !important; }
        }