:root {
    --primary: #E7000B;
    --bg: #FFFFFF;
    --text: #000000;
    --text-secondary: #505050;
    --card-bg: #FFFFFF;
    --card-border: #E5E5E5;
    --btn-secondary-bg: #F5F5F5;
    --btn-secondary-hover: #EBEBEB;
    --shadow: 0 2px 8px rgba(0, 0, 0, 0.05), 0 0 1px rgba(0, 0, 0, 0.1);
    --transition: 0.2s cubic-bezier(0.4, 0, 0.2, 1);
}

@media (prefers-color-scheme: dark) {
    :root {
        --bg: #000000;
        --text: #FFFFFF;
        --text-secondary: #A0A0A0;
        --card-bg: #111111;
        --card-border: #222222;
        --btn-secondary-bg: #1A1A1A;
        --btn-secondary-hover: #252525;
        --shadow: 0 4px 12px rgba(0, 0, 0, 0.5);
    }
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    -webkit-tap-highlight-color: transparent;
}

body {
    font-family: "Segoe UI", "SF Pro Display", -apple-system, BlinkMacSystemFont, Roboto, sans-serif;
    background-color: var(--bg);
    color: var(--text);
    min-height: 100dvh;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: flex-start;
    padding: 24px;
    padding-top: calc(8vh + env(safe-area-inset-top));
    padding-bottom: calc(24px + env(safe-area-inset-bottom));
    line-height: 1.5;
}

.card-container {
    width: 100%;
    max-width: 340px;
    position: relative;
}

.profile-card {
    background: var(--card-bg);
    border: 1px solid var(--card-border);
    border-radius: 8px;
    padding: 32px 24px;
    box-shadow: var(--shadow);
    display: none;
    flex-direction: column;
    align-items: center;
    opacity: 0;
    transform: translateY(10px);
    transition: var(--transition);
}

.profile-card.active {
    display: flex;
    opacity: 1;
    transform: translateY(0);
}

/* Header section */
.avatar-box {
    width: 80px;
    height: 80px;
    margin-bottom: 16px;
}

.avatar {
    width: 100%;
    height: 100%;
    border-radius: 50%;
    object-fit: cover;
    border: 1px solid var(--card-border);
}

.header-link {
    text-decoration: none;
    display: flex;
    flex-direction: column;
    align-items: center;
    width: 100%;
    transition: var(--transition);
}

.nickname {
    font-size: 1.25rem;
    font-weight: 600;
    margin-bottom: 8px;
    letter-spacing: -0.01em;
    color: var(--text);
    text-decoration: none;
    transition: var(--transition);
}

.header-link:hover .nickname {
    color: var(--primary);
}

.home-link {
    display: inline-flex;
    align-items: center;
    padding: 6px 16px;
    background: transparent;
    color: var(--primary);
    border: 1px solid var(--primary);
    border-radius: 4px;
    font-size: 0.8125rem;
    font-weight: 500;
    text-decoration: none;
    transition: var(--transition);
    margin-bottom: 24px;
}

.home-link:hover {
    background: var(--primary);
    color: #FFFFFF;
}

/* QR Section */
.qr-section {
    width: 100%;
    display: flex;
    flex-direction: column;
    align-items: center;
    margin-bottom: 24px;
}

.qr-box {
    width: 160px;
    height: 160px;
    background: #FFFFFF;
    padding: 8px;
    border: 1px solid #E5E5E5;
    border-radius: 4px;
    margin-bottom: 12px;
}

.qr-code {
    width: 100%;
    height: 100%;
}

.qq-display {
    font-size: 0.875rem;
    color: var(--text-secondary);
    cursor: pointer;
    padding: 4px 8px;
    border-radius: 4px;
    transition: var(--transition);
}

.qq-display:hover {
    background: var(--btn-secondary-bg);
    color: var(--primary);
}

/* Action Buttons */
.primary-btn {
    width: 100%;
    padding: 10px;
    background: var(--primary);
    color: #FFFFFF;
    border: none;
    border-radius: 4px;
    font-size: 0.9375rem;
    font-weight: 600;
    text-decoration: none;
    text-align: center;
    cursor: pointer;
    transition: var(--transition);
}

.primary-btn:hover {
    opacity: 0.9;
    box-shadow: 0 4px 12px rgba(231, 0, 11, 0.2);
}

/* Footer Selector */
.footer-selector {
    margin-top: 12px;
    width: 100%;
    max-width: 340px;
    display: flex;
    flex-direction: column;
    align-items: center;
}

.selector-toggle {
    width: 40px;
    height: 32px;
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    color: var(--text-secondary);
    transition: var(--transition);
    opacity: 0.6;
}

.selector-toggle:hover {
    opacity: 1;
    color: var(--primary);
}

.chevron {
    width: 20px;
    height: 20px;
    transition: transform 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

.selector-toggle.active .chevron {
    transform: rotate(180deg);
}

.footer-nav-wrapper {
    width: 100%;
    max-height: 0;
    overflow: hidden;
    opacity: 0;
    transition: max-height 0.4s cubic-bezier(0.4, 0, 0.2, 1),
        opacity 0.3s ease;
    visibility: hidden;
}

.footer-nav-wrapper.expanded {
    max-height: 100px;
    opacity: 1;
    visibility: visible;
    margin-top: 8px;
}

.footer-nav {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 12px;
    width: 100%;
}

.nav-item {
    padding: 8px;
    background: var(--card-bg);
    border: 1px solid var(--card-border);
    color: var(--text-secondary);
    font-size: 0.8125rem;
    font-weight: 500;
    border-radius: 4px;
    cursor: pointer;
    text-align: center;
    transition: var(--transition);
}

.nav-item:hover {
    border-color: var(--primary);
    color: var(--primary);
}

.nav-item.active {
    background: var(--btn-secondary-bg);
    border-color: var(--primary);
    color: var(--primary);
    font-weight: 600;
}

/* Toast */
.toast {
    position: fixed;
    bottom: 32px;
    background: #323130;
    color: #FFFFFF;
    padding: 8px 16px;
    border-radius: 4px;
    font-size: 0.875rem;
    box-shadow: 0 8px 16px rgba(0, 0, 0, 0.2);
    opacity: 0;
    transform: translateY(20px);
    transition: 0.3s ease;
    pointer-events: none;
    z-index: 1000;
}

.toast.show {
    opacity: 1;
    transform: translateY(0);
}

@media (prefers-color-scheme: dark) {
    .toast {
        background: #F3F2F1;
        color: #000000;
    }
}

.btn-group {
    width: 100%;
    display: flex;
    flex-direction: column;
    gap: 8px;
    margin-top: 4px;
}

.sponsor-btn {
    width: 100%;
    padding: 10px;
    background: var(--btn-secondary-bg);
    color: var(--text-secondary);
    border: 1px solid var(--card-border);
    border-radius: 4px;
    font-size: 0.9375rem;
    font-weight: 500;
    text-decoration: none;
    text-align: center;
    cursor: pointer;
    transition: var(--transition);
}

.sponsor-btn:hover {
    border-color: var(--primary);
    color: var(--primary);
    background: rgba(231, 0, 11, 0.05);
}