:root {
    /* Brand Colors (Bickle 팔레트) */
    --bickle-primary: #16d8a3;
    --bickle-primary-hover: #13be8f;
    --bickle-accent: #4f80ff;
    --bickle-bg-main: #ffffff;
    --bickle-bg-sub: #f9f9f9;
    --bickle-text-dark: #2c313d;
    --bickle-text-sub: #757b8a;
    --bickle-border: #e2e2e2;

    /* Font */
    --bickle-font: 'NanumSquareWebFont', 'NanumGothic', '맑은 고딕', sans-serif;
}

* {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
    font-family: var(--bickle-font);
}

body {
    background-color: var(--bickle-bg-main);
    color: var(--bickle-text-dark);
    line-height: 1.6;
}

/* 1. GNB Header (상단 네비게이션) */
.header {
    position: sticky;
    top: 0;
    z-index: 1000;
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(8px);
    border-bottom: 1px solid var(--bickle-border);
    height: 70px;
}

.header-container {
    max-width: 1200px;
    margin: 0 auto;
    height: 100%;
    display: grid;
    grid-template-columns: 1fr auto 1fr; /* 완벽 중앙 정렬 Grid */
    align-items: center;
    padding: 0 24px;
}

.logo {
    font-size: 24px;
    font-weight: 800;
    color: var(--bickle-primary);
    text-decoration: none;
    display: flex;
    align-items: center;
    gap: 8px;
    justify-self: start;
}

.nav-menu {
    display: flex;
    list-style: none;
    gap: 32px;
    justify-self: center;
}

.nav-link {
    text-decoration: none;
    color: var(--bickle-text-dark);
    font-weight: 600;
    font-size: 16px;
    position: relative;
    padding: 8px 0;
}

.nav-link::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 100%;
    height: 3px;
    background-color: var(--bickle-primary);
    transform: scaleX(0);
    transition: transform 0.2s ease-in-out;
    border-radius: 2px;
}

.nav-link:hover::after {
    transform: scaleX(1);
}

.header-actions {
    display: flex;
    gap: 12px;
    justify-self: end;
}

/* Common Button Styles */
.btn {
    padding: 10px 20px;
    border-radius: 6px;
    font-weight: 700;
    font-size: 14px;
    cursor: pointer;
    text-decoration: none;
    transition: all 0.2s ease;
    display: inline-flex;
    align-items: center;
    justify-content: center;
}

.btn-outline {
    border: 1px solid var(--bickle-border);
    background: transparent;
    color: var(--bickle-text-dark);
}

.btn-outline:hover {
    border-color: var(--bickle-primary);
    color: var(--bickle-primary);
}

.btn-primary {
    background-color: var(--bickle-primary);
    color: #ffffff;
    border: none;
    box-shadow: 0 4px 12px rgba(22, 216, 163, 0.25);
}

.btn-primary:hover {
    background-color: var(--bickle-primary-hover);
    transform: translateY(-1px);
}

/* 2. Footer */
.footer {
    background: var(--bickle-bg-sub);
    border-top: 1px solid var(--bickle-border);
    padding: 40px 24px;
    color: var(--bickle-text-sub);
    font-size: 14px;
}

.footer-container {
    max-width: 1200px;
    margin: 0 auto;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

/* ==========================================
   3. Auth Pages (로그인 / 회원가입 스타일)
   ========================================== */
.auth-container {
    max-width: 420px;
    width: 90%;
    margin: 60px auto;
    padding: 40px 32px;
    background-color: var(--bickle-bg-main);
    border: 1px solid var(--bickle-border);
    border-radius: 12px;
    box-shadow: 0 8px 24px rgba(0, 0, 0, 0.05);
    display: flex;
    flex-direction: column;
    align-items: center;
}

.auth-container h2 {
    margin-bottom: 28px;
    font-size: 24px;
    font-weight: 800;
    color: var(--bickle-text-dark);
    text-align: center;
}

.auth-container form {
    width: 100%;
    display: flex;
    flex-direction: column;
    gap: 16px;
}

.auth-container form > div {
    width: 100%;
}

.auth-container input {
    width: 100%;
    padding: 12px 16px;
    border: 1px solid var(--bickle-border);
    border-radius: 6px;
    font-size: 15px;
    font-family: var(--bickle-font);
    color: var(--bickle-text-dark);
    background-color: var(--bickle-bg-sub);
    transition: all 0.2s ease;
}

.auth-container input:focus {
    outline: none;
    border-color: var(--bickle-primary);
    background-color: var(--bickle-bg-main);
    box-shadow: 0 0 0 3px rgba(22, 216, 163, 0.15);
}

.auth-container .btn {
    width: 100%;
    padding: 12px;
    font-size: 15px;
    margin-top: 8px;
}

.auth-container p {
    margin-top: 24px;
    font-size: 14px;
    color: var(--bickle-text-sub);
    text-align: center;
}

.auth-container p a {
    color: var(--bickle-accent);
    text-decoration: none;
    font-weight: 700;
}

.auth-container p a:hover {
    text-decoration: underline;
}

/* Responsive */
@media (max-width: 768px) {
    .header-container {
        grid-template-columns: auto 1fr;
    }
    .nav-menu { 
        display: none; 
    }
}