:root{--bg-base: #F7F8FA;--surface: #FFFFFF;--surface-alt: #F1F3F7;--border: #E2E5EC;--border-strong: #C5CAD6;--text-primary: #1A2233;--text-secondary: #566075;--text-muted: #8A93A6;--text-on-accent: #FFFFFF;--accent: #4F46E5;--accent-hover: #4338CA;--accent-subtle: #EEF0FE;--focus-ring: #6366F1;--status-correct-color: #15803D;--status-correct-bg: #E7F6EC;--status-correct-on: #0B5128;--status-incorrect-color: #C2342B;--status-incorrect-bg: #FCEBEA;--status-incorrect-on: #7A1F19;--status-unstudied-color: #8A93A6;--status-review-color: #B45309;--status-review-bg: #FDF2E3;--status-review-on: #7A3A06;--status-progress-color: #4F46E5;--status-progress-bg: #EEF0FE;--band-low-color: #B45309;--band-mid-color: #4F46E5;--band-high-color: #15803D;--font-base: "Hiragino Kaku Gothic ProN", "Noto Sans JP", -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;--font-numeric: "SF Pro Display", system-ui, sans-serif;--text-base: 16px;--lh-body: 1.7;--lh-tight: 1.35;--sp-xs: 4px;--sp-sm: 8px;--sp-md: 12px;--sp-lg: 16px;--sp-xl: 24px;--sp-xxl: 32px;--screen-pad: 16px;--content-max: 720px;--radius-sm: 6px;--radius-md: 10px;--radius-lg: 14px;--radius-pill: 999px;--shadow-card: 0 1px 2px rgba(16, 24, 40, .04), 0 1px 3px rgba(16, 24, 40, .06);--shadow-popover: 0 8px 24px rgba(16, 24, 40, .12);--shadow-bottom-nav: 0 -1px 0 rgba(16, 24, 40, .06);--bottom-nav-height: 60px;--dur-fast: .12s;--dur-base: .2s;--ease: cubic-bezier(.4, 0, .2, 1);--timer-warning-color: #B45309;--timer-danger-color: #C2342B}@media (prefers-reduced-motion: reduce){*,*:before,*:after{animation-duration:.01ms!important;animation-iteration-count:1!important;transition-duration:.01ms!important}}*,*:before,*:after{box-sizing:border-box}html,body{margin:0;padding:0;height:100%}body{font-family:var(--font-base);font-size:var(--text-base);line-height:var(--lh-body);color:var(--text-primary);background:var(--bg-base);-webkit-font-smoothing:antialiased;-moz-osx-font-smoothing:grayscale}#root{height:100%}a{color:var(--accent);text-decoration:none}a:hover{text-decoration:underline}button{font-family:var(--font-base);cursor:pointer}input,textarea,select{font-family:var(--font-base);font-size:var(--text-base)}:focus-visible{outline:2px solid var(--focus-ring);outline-offset:2px}