*, *::before, *::after {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

:root {
    --bg: #100d28;
    --surface: rgba(255, 255, 255, 0.05);
    --border: rgba(255, 255, 255, 0.12);
    --text: #ddd9f5;
    --text-muted: rgba(221, 217, 245, 0.35);
    --accent-blue: #5b73d4;
    --accent-purple: #8b4ec5;
    --blue-glow: rgba(91, 115, 212, 0.45);
    --purple-glow: rgba(139, 78, 197, 0.4);
}

body {
    background-color: var(--bg);
    background-image:
        radial-gradient(ellipse at 30% 20%, rgba(60, 40, 120, 0.45) 0%, transparent 55%),
        radial-gradient(ellipse at 75% 80%, rgba(25, 15, 75, 0.45) 0%, transparent 55%);
    color: var(--text);
    font-family: 'Hiragino Kaku Gothic ProN', 'Noto Sans JP', 'Yu Gothic', sans-serif;
    min-height: 100svh;
}

/* ===== App Layout ===== */
.app {
    display: flex;
    flex-direction: column;
    min-height: 100svh;
    max-width: 480px;
    margin: 0 auto;
    padding: 0 20px;
}

/* ===== Header ===== */
.app-header {
    padding: 24px 0 18px;
    text-align: center;
}

.app-title {
    font-size: 1.3rem;
    font-weight: 300;
    letter-spacing: 0.35em;
    opacity: 0.9;
}

/* ===== Main ===== */
.app-main {
    flex: 1;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    gap: 40px;
    padding: 20px 0;
}

/* ===== Card ===== */
.card-scene {
    perspective: 800px;
    width: 200px;
    height: 200px;
}

.card {
    width: 100%;
    height: 100%;
    position: relative;
    transform-style: preserve-3d;
    transition: transform 0.55s cubic-bezier(0.45, 0.05, 0.55, 0.95);
}

.card.is-blind {
    transform: rotateY(180deg);
}

.card-face {
    position: absolute;
    inset: 0;
    border-radius: 20px;
    display: flex;
    align-items: center;
    justify-content: center;
    -webkit-backface-visibility: hidden;
    backface-visibility: hidden;
}

.card-front {
    background: var(--surface);
    border: 1px solid var(--border);
    box-shadow:
        0 4px 24px rgba(0, 0, 0, 0.5),
        inset 0 1px 0 rgba(255, 255, 255, 0.07);
}

.card-back {
    background: linear-gradient(135deg, rgba(28, 14, 68, 0.9) 0%, rgba(50, 20, 100, 0.9) 100%);
    border: 1px solid rgba(139, 78, 197, 0.35);
    transform: rotateY(180deg);
    overflow: hidden;
    box-shadow: 0 4px 24px rgba(0, 0, 0, 0.5);
}

.card-back-pattern {
    position: absolute;
    inset: 0;
    background-image:
        repeating-linear-gradient(
            45deg,
            rgba(139, 78, 197, 0.12) 0px,
            rgba(139, 78, 197, 0.12) 1px,
            transparent 1px,
            transparent 14px
        ),
        repeating-linear-gradient(
            -45deg,
            rgba(91, 115, 212, 0.12) 0px,
            rgba(91, 115, 212, 0.12) 1px,
            transparent 1px,
            transparent 14px
        );
}

/* ===== Number ===== */
.number {
    font-size: clamp(3.5rem, 18vw, 5rem);
    font-weight: 700;
    letter-spacing: -0.02em;
    font-variant-numeric: tabular-nums;
    text-shadow: 0 0 28px var(--blue-glow);
    color: var(--text);
}

.number.pop {
    animation: numPop 0.38s cubic-bezier(0.34, 1.56, 0.64, 1);
}

@keyframes numPop {
    from { transform: scale(0.55); opacity: 0; }
    to   { transform: scale(1);    opacity: 1; }
}

/* ===== Controls ===== */
.controls {
    display: flex;
    gap: 16px;
    align-items: center;
}

.btn {
    padding: 13px 26px;
    min-width: 115px;
    border-radius: 50px;
    border: 1px solid transparent;
    font-size: 0.95rem;
    font-family: inherit;
    font-weight: 500;
    letter-spacing: 0.05em;
    color: var(--text);
    cursor: pointer;
    transition: background-color 0.2s, box-shadow 0.2s, transform 0.1s, opacity 0.2s;
    -webkit-tap-highlight-color: transparent;
}

.btn:active:not(:disabled) {
    transform: scale(0.94);
}

.btn:disabled {
    opacity: 0.3;
    cursor: not-allowed;
}

.btn-draw {
    background: rgba(91, 115, 212, 0.18);
    border-color: rgba(91, 115, 212, 0.5);
}

.btn-draw:hover:not(:disabled) {
    background: rgba(91, 115, 212, 0.32);
    box-shadow: 0 0 18px rgba(91, 115, 212, 0.35);
}

.btn-blind {
    background: rgba(139, 78, 197, 0.18);
    border-color: rgba(139, 78, 197, 0.5);
}

.btn-blind:hover:not(:disabled) {
    background: rgba(139, 78, 197, 0.32);
    box-shadow: 0 0 18px rgba(139, 78, 197, 0.35);
}

/* ===== Footer / Memo ===== */
.app-footer {
    padding: 16px 0 28px;
}

.memo-area {
    border-radius: 14px;
    background: rgba(0, 0, 0, 0.22);
    border: 1px solid var(--border);
    overflow: hidden;
    transition: border-color 0.2s, box-shadow 0.2s;
    min-height: 88px;
}

.memo-area:hover {
    border-color: rgba(255, 255, 255, 0.22);
}

.memo-area.is-editing {
    border-color: var(--accent-blue);
    box-shadow: 0 0 0 3px rgba(91, 115, 212, 0.2);
}

.memo-display {
    padding: 16px;
    min-height: 88px;
    cursor: pointer;
    font-size: 0.9rem;
    line-height: 1.75;
    white-space: pre-wrap;
    word-break: break-word;
    color: var(--text);
}

.memo-display.is-placeholder {
    color: var(--text-muted);
}

.memo-area.is-editing .memo-display {
    display: none;
}

.memo-input {
    display: none;
    width: 100%;
    min-height: 88px;
    padding: 16px;
    background: transparent;
    border: none;
    outline: none;
    color: var(--text);
    font-size: 0.9rem;
    font-family: inherit;
    line-height: 1.75;
    resize: none;
}

.memo-area.is-editing .memo-input {
    display: block;
}

/* ===== Responsive ===== */
@media (max-height: 580px) {
    .app-main { gap: 24px; }
    .card-scene { width: 160px; height: 160px; }
    .app-header { padding: 14px 0 10px; }
}