/* =============================================
   Design Tokens (main.css와 동일한 시스템)
============================================= */
:root {
    --color-bg: #f7f6f2;
    --color-surface: #ffffff;
    --color-surface-hover: #f3f7f5;
    --color-border: #d4d1ca;
    --color-text: #28251d;
    --color-text-muted: #7a7974;
    --color-primary: #01696f;
    --color-primary-hover: #0c4e54;
    --color-primary-highlight: #cedcd8;
    --color-success: #437a22;
    --color-success-highlight: #d4dfcc;
    --color-error: #a12c7b;
    --color-error-highlight: #f5e6f0;
    --radius-sm: 0.375rem;
    --radius-md: 0.5rem;
    --radius-lg: 0.75rem;
    --radius-xl: 1rem;
    --shadow-md: 0 4px 16px oklch(0.2 0.01 80 / 0.09);
    --shadow-lg: 0 8px 32px oklch(0.2 0.01 80 / 0.13);
    --transition: 180ms cubic-bezier(0.16, 1, 0.3, 1);
    --text-sm: clamp(0.875rem, 0.8rem + 0.35vw, 1rem);
    --text-base: clamp(1rem, 0.95rem + 0.25vw, 1.125rem);
    --text-lg: clamp(1.125rem, 1rem + 0.75vw, 1.5rem);
    --space-1: 0.25rem;
    --space-2: 0.5rem;
    --space-3: 0.75rem;
    --space-4: 1rem;
    --space-5: 1.25rem;
    --space-6: 1.5rem;
    --space-8: 2rem;
    --space-10: 2.5rem;
}

/* =============================================
   Base Reset
============================================= */
*, *::before, *::after {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

html {
    -webkit-font-smoothing: antialiased;
    scroll-behavior: smooth;
}

body {
    min-height: 100dvh;
    background-color: var(--color-bg);
    font-family: 'Pretendard', 'Apple SD Gothic Neo', 'Malgun Gothic', sans-serif;
    color: var(--color-text);
    display: flex;
    align-items: center;
    justify-content: center;
    padding: var(--space-8) var(--space-4);
}

a { text-decoration: none; color: inherit; }
button { cursor: pointer; background: none; border: none; font: inherit; }
img { display: block; max-width: 100%; height: auto; }

/* =============================================
   Layout
============================================= */
.join-wrapper {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: var(--space-8);
    width: 100%;
    max-width: 480px;
}

/* =============================================
   Logo
============================================= */
.logo-area img {
    width: clamp(160px, 40vw, 240px);
    height: auto;
    object-fit: contain;
}

/* =============================================
   Join Card
============================================= */
.join-card {
    background: var(--color-surface);
    border: 1px solid oklch(from #28251d l c h / 0.10);
    border-radius: var(--radius-xl);
    box-shadow: var(--shadow-md);
    padding: var(--space-8) var(--space-8);
    width: 100%;
    display: flex;
    flex-direction: column;
    gap: var(--space-6);
}

.join-card__header {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: var(--space-3);
    text-align: center;
}

.join-card__icon {
    width: 52px;
    height: 52px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--color-primary-highlight);
    border-radius: var(--radius-lg);
    color: var(--color-primary);
}

.join-card__icon svg {
    width: 26px;
    height: 26px;
    stroke-width: 1.75;
}

.join-card__title {
    font-size: var(--text-lg);
    font-weight: 700;
    color: var(--color-text);
    line-height: 1.2;
}

.join-card__desc {
    font-size: var(--text-sm);
    color: var(--color-text-muted);
}

/* =============================================
   Form
============================================= */
form {
    display: flex;
    flex-direction: column;
    gap: var(--space-5);
}

.form-group {
    display: flex;
    flex-direction: column;
    gap: var(--space-2);
}

.form-label {
    display: flex;
    align-items: center;
    gap: var(--space-2);
    font-size: var(--text-sm);
    font-weight: 600;
    color: var(--color-text);
}

.form-label svg {
    width: 15px;
    height: 15px;
    color: var(--color-text-muted);
    stroke-width: 2;
    flex-shrink: 0;
}

/* 입력 + 버튼 행 */
.input-row {
    display: flex;
    gap: var(--space-2);
    align-items: stretch;
}

.input-row--single {
    position: relative;
}

.input-row--single .form-input {
    padding-right: 2.75rem;
}

/* 입력 필드 */
.form-input {
    width: 100%;
    padding: var(--space-3) var(--space-4);
    font-size: var(--text-sm);
    color: var(--color-text);
    background: var(--color-bg);
    border: 1.5px solid var(--color-border);
    border-radius: var(--radius-md);
    outline: none;
    transition:
        border-color var(--transition),
        box-shadow var(--transition),
        background var(--transition);
    line-height: 1.5;
}

.form-input::placeholder {
    color: var(--color-text-muted);
    font-size: clamp(0.75rem, 0.7rem + 0.2vw, 0.875rem);
}

.form-input:focus {
    border-color: var(--color-primary);
    background: var(--color-surface);
    box-shadow: 0 0 0 3px oklch(from #01696f l c h / 0.15);
}

/* 유효성 상태 */
.form-input.is-valid {
    border-color: var(--color-success);
    background: #f7fbf4;
}

.form-input.is-invalid {
    border-color: var(--color-error);
    background: var(--color-error-highlight);
}

/* 피드백 메시지 */
.form-feedback {
    display: block;
    min-height: 1.2em;
    font-size: clamp(0.75rem, 0.7rem + 0.2vw, 0.8rem);
    line-height: 1.4;
    padding-left: var(--space-1);
    transition: color var(--transition);
}

.form-feedback.ok {
    color: var(--color-success);
}

.form-feedback.err {
    color: var(--color-error);
}

/* 중복 확인 버튼 */
.btn-check {
    flex-shrink: 0;
    padding: var(--space-3) var(--space-4);
    font-size: var(--text-sm);
    font-weight: 600;
    color: var(--color-primary);
    border: 1.5px solid var(--color-primary);
    border-radius: var(--radius-md);
    background: transparent;
    white-space: nowrap;
    transition:
        background var(--transition),
        color var(--transition),
        border-color var(--transition);
}

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

.btn-check:active {
    opacity: 0.8;
}

.btn-check:disabled {
    opacity: 0.45;
    cursor: not-allowed;
}

/* 비밀번호 눈 아이콘 버튼 */
.btn-eye {
    position: absolute;
    right: var(--space-3);
    top: 50%;
    transform: translateY(-50%);
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--color-text-muted);
    padding: var(--space-1);
    transition: color var(--transition);
}

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

.btn-eye svg {
    width: 18px;
    height: 18px;
    stroke-width: 1.75;
}

/* =============================================
   Submit Button
============================================= */
.btn-submit {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: var(--space-2);
    width: 100%;
    padding: var(--space-4) var(--space-6);
    font-size: var(--text-base);
    font-weight: 700;
    color: #ffffff;
    background: var(--color-primary);
    border: none;
    border-radius: var(--radius-lg);
    margin-top: var(--space-2);
    transition:
        background var(--transition),
        box-shadow var(--transition),
        transform var(--transition);
    cursor: pointer;
}

.btn-submit svg {
    width: 18px;
    height: 18px;
    stroke-width: 2;
}

.btn-submit:hover {
    background: var(--color-primary-hover);
    box-shadow: var(--shadow-md);
    transform: translateY(-1px);
}

.btn-submit:active {
    transform: translateY(0);
    opacity: 0.9;
}

.btn-submit:disabled {
    background: var(--color-border);
    cursor: not-allowed;
    transform: none;
    box-shadow: none;
}

/* =============================================
   로그인 링크
============================================= */
.join-card__login-link {
    font-size: var(--text-sm);
    color: var(--color-text-muted);
    text-align: center;
}

.join-card__login-link a {
    color: var(--color-primary);
    font-weight: 600;
    transition: color var(--transition);
}

.join-card__login-link a:hover {
    color: var(--color-primary-hover);
    text-decoration: underline;
}

/* =============================================
   Responsive — 모바일
============================================= */
@media (max-width: 480px) {
    body {
        align-items: flex-start;
        padding-top: var(--space-6);
    }

    .join-card {
        padding: var(--space-6) var(--space-5);
        border-radius: var(--radius-lg);
    }

    .input-row {
        flex-direction: column;
    }

    .btn-check {
        width: 100%;
    }
}