:root {
    --bg-primary: #f7fafc;
    /* very light background */
    --bg-secondary: #ffffff;
    /* cards/surfaces */
    --bg-tertiary: #f1f5f9;
    /* subtle sections */
    --text-primary: #0f172a;
    /* near-black */
    --text-secondary: #334155;
    /* slate */
    --text-muted: #64748b;
    /* muted slate */
    --border-color: #e2e8f0;
    /* light border */
    --symbol-color: #9659ff;
    /* purple */
    --symbol-secondary: #a78bfa;
    /* light purple */
    --success: #10b981;
    --error: #ef4444;
    --warning: #f59e0b;

    --symbol-gradient: linear-gradient(135deg, var(--symbol-color) 0%, #8b5cf6 40%, var(--symbol-secondary) 100%);
    --symbol-shadow: 0 6px 18px rgba(124, 58, 237, 0.24), 0 2px 6px rgba(124, 58, 237, 0.16);
    --btn-shadow: 0 8px 20px rgba(124, 58, 237, 0.30);
    --symbol-accent-shadow: 0 6px 18px #7c3aed46, 0 2px 6px rgba(124, 58, 237, 0.16);
}

body {
    overflow: hidden;
}

/* ─── 텍스트 유틸리티 ─────────────────────────────────────────── */
.text-title {
    color: var(--text-primary);
    font-size: 2rem;
    line-height: 1.5;
    font-weight: 1000;
}

.text-primary {
    color: var(--text-primary);
    font-size: 1.5rem;
    line-height: 1.5;
    font-weight: 500;
}

.text-secondary {
    color: var(--text-secondary);
    font-size: 1rem;
    line-height: 1.5;
    font-weight: 400;
}

.text-muted {
    color: var(--text-muted);
    font-size: 0.875rem;
    line-height: 1.5;
    font-weight: 300;
}

.text-accent {
    color: var(--symbol-color);
    font-size: 1rem;
    font-weight: 600;
    line-height: 1.5;
}


/* ─── symbol-color (보라 포그라운드) ───────────────────────────── */
.symbol-color {
    color: var(--symbol-color);
    fill: currentColor;
    stroke: currentColor;
}

/* ─── symbol-gradient (배경 그라데이션) ───────────────────────── */
.symbol-gradient {
    background-image: var(--symbol-gradient);
    color: #ffffff;
}

/* ─── symbol-box-shadow (보라 글로우) ──────────────────────────── */
.symbol-box-shadow {
    box-shadow: var(--symbol-shadow);
}

/* ─── 공통 버튼 베이스 ─────────────────────────────────────────── */
/* CSS에는 @extend가 없으므로, 베이스 스타일을
   .symbol-btn / .normal-btn에도 함께 적용되도록 묶어줌 */
.button-base,
.symbol-btn,
.normal-btn,
.small-dark-btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
    padding: 1rem 1rem;
    border: 0px solid transparent;
    border-radius: 0.75rem;
    font-weight: 600;
    line-height: 1;
    cursor: pointer;
    user-select: none;
    transition: 120ms ease;
    text-decoration: none;
}

.invisible-btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    user-select: none;
    background-color: transparent;
    border: transparent;
    color: var(--text-secondary);
}

.a-remove {
    all: unset;
    display: inline;
    cursor: pointer;
    text-decoration: none;
    color: inherit;
}

/* ─── symbol-btn (그라데이션 버튼) ────────────────────────────── */
.symbol-btn {
    background-image: var(--symbol-gradient);
    color: #ffffff;
    box-shadow: var(--btn-shadow);
}

.symbol-btn:hover {
    transform: translateY(-1px);
    opacity: 0.95;
}

.symbol-btn:active {
    transform: translateY(0);
    opacity: 0.92;
    box-shadow: 0 4px 10px rgba(124, 58, 237, 0.25);
}

.symbol-btn:focus-visible {
    outline: 2px solid rgba(167, 139, 250, 0.9);
    outline-offset: 2px;
}

/* 고스트 변형 */
.symbol-btn.ghost {
    background: transparent;
    color: var(--symbol-color);
    border-color: rgba(124, 58, 237, 0.35);
}

.symbol-btn.ghost:hover {
    background: rgba(124, 58, 237, 0.08);
}

/* ─── normal-btn (일반 버튼) ──────────────────────────────────── */
.normal-btn {
    background-color: var(--bg-secondary);
    color: var(--text-primary);
    border-color: var(--border-color);
    box-shadow: 0 2px 6px rgba(15, 23, 42, 0.06);
}

.normal-btn:hover {
    background-color: var(--bg-tertiary);
}

.normal-btn:active {
    transform: translateY(1px);
    box-shadow: 0 1px 3px rgba(15, 23, 42, 0.08);
}

.normal-btn:focus-visible {
    outline: 2px solid var(--border-color);
    outline-offset: 2px;
}


.small-dark-btn {
    background-color: rgba(0, 0, 0, 0.55);
    color: rgba(255, 255, 255, 0.95);
    border: 1px solid rgba(255, 255, 255, 0.16);
    border-radius: 8px;
    padding: 0.1rem;
    box-shadow: 0 2px 6px rgba(0, 0, 0, 0.25);
    backdrop-filter: blur(4px);
    width: 25px;
    height: 25px;
}

.small-dark-btn:hover {
    background-color: rgba(0, 0, 0, 0.65);
}

.small-dark-btn:active {
    transform: translateY(1px);
    box-shadow: 0 1px 3px rgba(0, 0, 0, 0.3);
}

.small-dark-btn:focus-visible {
    outline: 2px solid rgba(255, 255, 255, 0.25);
    outline-offset: 2px;
}


.invisible-btn:hover {
    color: var(--text-muted);
}

/* ─── Base Inputs ───────────────────────────────────────────── */
.input,
.select,
.textarea {
    display: block;
    width: 100%;
    padding: 0.625rem 0.75rem;
    border: 2px solid var(--border-color);
    border-radius: 0.5rem;
    background-color: var(--bg-secondary);
    color: var(--text-primary);
    line-height: 1.5;
    outline: none;
    transition: 120ms ease;
}

.input::placeholder,
.textarea::placeholder {
    color: var(--text-muted);
}

/* focus */
.input:focus-visible,
.select:focus-visible,
.textarea:focus-visible {
    border-color: var(--symbol-color);
    box-shadow: var(--symbol-shadow);
}

/* disabled */
.input:disabled,
.select:disabled,
.textarea:disabled {
    background-color: var(--bg-tertiary);
    color: var(--text-muted);
    cursor: not-allowed;
    opacity: 0.8;
}

/* ─── Sizes ─────────────────────────────────────────────────── */
.is-sm {
    padding: 0.5rem 0.625rem;
    font-size: 0.875rem;
}

.is-md {
    /* 기본값과 동일 — 필요 시 명시 */
    padding: 0.625rem 0.75rem;
    font-size: 1rem;
}

.is-lg {
    padding: 0.75rem 0.875rem;
    font-size: 1.0625rem;
}

/* ─── States (additive classes) ─────────────────────────────── */
.is-error {
    border-color: var(--error);
    box-shadow: 0 0 0 3px rgba(239, 68, 68, 0.15);
}

.is-success {
    border-color: var(--success);
    box-shadow: 0 0 0 3px rgba(16, 185, 129, 0.15);
}

.is-warning {
    border-color: var(--warning);
    box-shadow: 0 0 0 3px rgba(245, 158, 11, 0.15);
}

/* ─── Variants ──────────────────────────────────────────────── */
.input-ghost,
.textarea-ghost,
.select-ghost {
    background-color: transparent;
    border-color: rgba(15, 23, 42, 0.08);
}

.input-ghost:focus-visible,
.textarea-ghost:focus-visible,
.select-ghost:focus-visible {
    border-color: var(--symbol-color);
    box-shadow: 0 0 0 3px rgba(124, 58, 237, 0.12);
}

.radio-label {
    font-size: 18px;
    line-height: 2rem;
    padding: 0.2em 0.4em;
}

[type="radio"],
span {
    vertical-align: middle;
}

[type="radio"] {
    vertical-align: middle;
    appearance: none;
}

[type="radio"] {
    vertical-align: middle;
    appearance: none;
    border: max(2px, 0.1em) solid gray;
    border-radius: 50%;
    width: 1.25em;
    height: 1.25em;
}

[type="radio"]:checked {
    border: 0.4em solid var(--symbol-color);
}

[type="radio"]:focus-visible {
    outline: max(2px, 0.1em) dotted tomato;
    outline-offset: max(2px, 0.1em);
}

[type="radio"]:hover {
    box-shadow: 0 0 0 max(4px, 0.2em) lightgray;
    cursor: pointer;
}

[type="radio"]:hover+span {
    cursor: pointer;
}

[type="radio"] {
    vertical-align: middle;
    appearance: none;
    border: max(2px, 0.1em) solid gray;
    border-radius: 50%;
    width: 1.25em;
    height: 1.25em;
    transition: border 200ms ease-in-out;
}