/* ============================================
   CSS 변수: 테마는 여기서 한 번에 관리
   ============================================ */
:root {
    /* 색상 */
    --color-bg: #f7f8fa;
    --color-surface: #ffffff;
    --color-text: #1a1a1a;
    --color-text-muted: #6b7280;
    --color-border: #e5e7eb;

    --color-primary: #3b82f6;
    --color-primary-hover: #2563eb;

    --color-kakao-bg: #fee500;
    --color-kakao-text: #191919;
    --color-kakao-hover: #fdd835;

    --color-error-bg: #fef2f2;
    --color-error-text: #b91c1c;
    --color-error-border: #fecaca;

    /* 간격 */
    --space-xs: 0.5rem;
    --space-sm: 0.75rem;
    --space-md: 1rem;
    --space-lg: 1.5rem;
    --space-xl: 2rem;

    /* 모양 */
    --radius-sm: 6px;
    --radius-md: 12px;
    --radius-lg: 16px;

    /* 그림자 */
    --shadow-card: 0 4px 20px rgba(0, 0, 0, 0.06);

    /* 폰트 */
    --font-family: -apple-system, BlinkMacSystemFont, "Segoe UI",
    "Noto Sans KR", Roboto, sans-serif;
}

/* ============================================
   Reset
   ============================================ */
* {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

body {
    font-family: var(--font-family);
    background-color: var(--color-bg);
    color: var(--color-text);
    line-height: 1.5;
    -webkit-font-smoothing: antialiased;
}

a {
    text-decoration: none;
    color: inherit;
}

button {
    font-family: inherit;
}

/* ============================================
   Layout
   ============================================ */
.container {
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: var(--space-md);
}

.container--top {
    min-height: auto;
    align-items: flex-start;
    flex-direction: column;
    max-width: 960px;
    margin: 0 auto;
    padding: var(--space-xl) var(--space-lg);
}

/* ============================================
   Buttons (재사용 컴포넌트)
   ============================================ */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: var(--space-xs);
    width: 100%;
    padding: var(--space-sm) var(--space-lg);
    border: none;
    border-radius: var(--radius-md);
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: background-color 0.15s ease, transform 0.05s ease;
}

.btn:active {
    transform: scale(0.98);
}

.btn--primary {
    background-color: var(--color-primary);
    color: white;
    max-width: 200px;
}

.btn--primary:hover {
    background-color: var(--color-primary-hover);
}

.btn--kakao {
    background-color: var(--color-kakao-bg);
    color: var(--color-kakao-text);
    margin-bottom: var(--space-md);
}

.btn--kakao:hover {
    background-color: var(--color-kakao-hover);
}

.btn__icon {
    font-size: 1.125rem;
}

.btn-text {
    background: none;
    border: none;
    font-size: 0.9rem;
    color: var(--color-text-muted);
    cursor: pointer;
    padding: var(--space-xs);
}

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

/* ============================================
   Alert (재사용 컴포넌트)
   ============================================ */
.alert {
    padding: var(--space-sm) var(--space-md);
    border-radius: var(--radius-sm);
    font-size: 0.9rem;
    margin-bottom: var(--space-md);
    border: 1px solid transparent;
}

.alert--error {
    background-color: var(--color-error-bg);
    color: var(--color-error-text);
    border-color: var(--color-error-border);
}

/* ============================================
   Link (재사용 컴포넌트)
   ============================================ */
.link {
    display: inline-block;
    margin-top: var(--space-md);
    font-size: 0.9rem;
}

.link--muted {
    color: var(--color-text-muted);
}

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

/* ============================================
   유틸리티
   ============================================ */
.no-scrollbar {
    -ms-overflow-style: none;
    scrollbar-width: none;
}

.no-scrollbar::-webkit-scrollbar {
    display: none;
}