/* ========================================
   Design System - Dark Only
   Font: Inter + JetBrains Mono
   ======================================== */
@import url('https://fonts.googleapis.com/css2?family=Inter:wght@300;400;500;600;700&family=JetBrains+Mono:wght@400;500;600&display=swap');

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

/* CSS Variables - Dark Only Design System */
:root {
    /* Background */
    --bg-primary: #0D1117;
    --bg-secondary: #161B22;
    --bg-tertiary: #21262D;

    /* Text */
    --text-primary: #F0F6FC;
    --text-secondary: #8B949E;
    --text-muted: #484F58;

    /* Borders */
    --border-color: #30363D;
    --border-light: #21262D;

    /* Semantic Colors */
    --success-color: #00C853;
    --danger-color: #FF5252;
    --warning-color: #FFB300;
    --info-color: #2196F3;
    --accent-color: #00D9FF;

    /* Backward-compatible aliases */
    --header-bg: #161B22;
    --header-text: #F0F6FC;
    --card-bg: #161B22;
    --card-shadow: rgba(0, 0, 0, 0.3);
    --input-bg: #0D1117;
    --input-border: #30363D;
    --table-header-bg: #161B22;
    --table-hover: #21262D;
    --modal-bg: #161B22;
    --modal-overlay: rgba(0, 0, 0, 0.7);

    /* Transition */
    --transition: 150ms ease-out;
}

html {
    font-size: 16px;
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    line-height: 1.6;
    color: var(--text-primary);
    background-color: var(--bg-primary);
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

/* Utility Classes */
.monospace {
    font-family: 'JetBrains Mono', monospace;
}

/* Skeleton Loading Animation */
@keyframes skeleton-pulse {
    0% { opacity: 0.6; }
    50% { opacity: 0.3; }
    100% { opacity: 0.6; }
}

.skeleton {
    background: var(--bg-tertiary);
    animation: skeleton-pulse 1.5s ease-in-out infinite;
    border-radius: 4px;
}

/* Header & Navigation */
.header {
    background-color: var(--header-bg);
    color: var(--header-text);
    position: sticky;
    top: 0;
    z-index: 1000;
    border-bottom: 1px solid var(--border-color);
}

/* Nav Left (push others to right) */
.nav-left {
    margin-left: 0.7rem;
    margin-right: 0.5rem;
}

.nav-update-time {
    font-size: 0.7rem;
    color: rgba(255, 255, 255, 0.5);
    margin-right: auto;
}

/* Nav Icon Button (Refresh) */
.nav-icon-btn {
    background: transparent;
    border: 1px solid rgba(255, 255, 255, 0.2);
    border-radius: 4px;
    width: 32px;
    height: 32px;
    min-width: 32px;
    min-height: 32px;
    padding: 0;
    cursor: pointer;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    margin-right: 0.5rem;
    transition: all var(--transition);
    font-size: 1.1rem;
    color: rgba(255, 255, 255, 0.7);
    outline: none;
    position: relative;
}

.nav-icon-btn:hover {
    background: rgba(255, 255, 255, 0.08);
    border-color: rgba(255, 255, 255, 0.3);
    color: #fff;
}

.nav-icon-btn:active {
    background: rgba(255, 255, 255, 0.12);
    transform: scale(0.96);
}

.nav-icon-btn:focus-visible {
    outline: 2px solid var(--accent-color);
    outline-offset: 2px;
}

/* Refresh animation */
.nav-icon-btn.refreshing {
    animation: nav-btn-spin 0.8s linear infinite;
}

@keyframes nav-btn-spin {
    from { transform: rotate(0deg); }
    to { transform: rotate(360deg); }
}

.nav {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1rem;
    max-width: 1200px;
    margin: 0 auto;
}

.nav-brand {
    font-size: 1.5rem;
    font-weight: bold;
}

/* Nav Toggle (Hamburger Menu) */
.nav-toggle {
    display: none;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    background: transparent;
    border: 1px solid rgba(255, 255, 255, 0.2);
    border-radius: 4px;
    width: 32px;
    height: 32px;
    min-width: 32px;
    min-height: 32px;
    cursor: pointer;
    padding: 0;
    margin-right: 0.7rem;
    transition: all var(--transition);
    outline: none;
    position: relative;
}

.nav-toggle:hover {
    background: rgba(255, 255, 255, 0.08);
    border-color: rgba(255, 255, 255, 0.3);
}

.nav-toggle:active {
    background: rgba(255, 255, 255, 0.12);
    transform: scale(0.96);
}

.nav-toggle:focus-visible {
    outline: 2px solid var(--accent-color);
    outline-offset: 2px;
}

.nav-toggle span {
    display: block;
    width: 16px;
    height: 2px;
    background-color: rgba(255, 255, 255, 0.7);
    margin: 2px 0;
    transition: all 0.3s cubic-bezier(0.645, 0.045, 0.355, 1);
    border-radius: 1px;
}

.nav-toggle:hover span {
    background-color: #fff;
}

/* Hamburger to X animation */
.nav-toggle.active span:nth-child(1) {
    transform: rotate(45deg) translate(4px, 4px);
}

.nav-toggle.active span:nth-child(2) {
    opacity: 0;
    transform: scaleX(0);
}

.nav-toggle.active span:nth-child(3) {
    transform: rotate(-45deg) translate(4px, -4px);
}

.nav-menu {
    display: flex;
    list-style: none;
    gap: 1.5rem;
}

.nav-menu a {
    color: rgba(255, 255, 255, 0.85);
    text-decoration: none;
    padding: 0.5rem;
    transition: all var(--transition);
}

.nav-menu a:hover {
    color: var(--accent-color);
    opacity: 1;
}

/* Main Content */
.main-content {
    flex: 1;
    padding: 1rem;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
}

/* Hero Section */
.hero {
    text-align: center;
    padding: 3rem 1rem;
    background: linear-gradient(135deg, var(--bg-secondary), var(--bg-tertiary));
    color: var(--text-primary);
    border-radius: 8px;
    margin-bottom: 2rem;
    border: 1px solid var(--border-color);
}

.hero h1 {
    font-size: 1.8rem;
    margin-bottom: 0.5rem;
}

/* Card Section */
.card-section {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 1rem;
}

.card {
    background: var(--card-bg);
    padding: 1.5rem;
    border-radius: 8px;
    box-shadow: none;
    border: 1px solid var(--border-color);
    transition: all var(--transition);
}

.card:hover {
    transform: translateY(-2px);
    border-color: var(--accent-color);
}

.card h3 {
    color: var(--accent-color);
    margin-bottom: 0.5rem;
}

/* Footer */
.footer {
    background-color: var(--bg-secondary);
    color: var(--text-secondary);
    text-align: center;
    padding: 1rem;
    margin-top: auto;
    border-top: 1px solid var(--border-color);
}

/* Mobile Responsive */
@media (max-width: 768px) {
    .nav-toggle {
        display: flex;
    }

    .nav-menu {
        display: none;
        position: absolute;
        top: calc(100% + 4px);
        left: 0.7rem;
        right: 0.7rem;
        background: var(--bg-secondary);
        flex-direction: column;
        padding: 4px;
        gap: 0;
        border-radius: 8px;
        box-shadow: 0 6px 16px 0 rgba(0, 0, 0, 0.4),
                    0 3px 6px -4px rgba(0, 0, 0, 0.3),
                    0 9px 28px 8px rgba(0, 0, 0, 0.2);
        border: 1px solid var(--border-color);
        z-index: 1000;
    }

    .nav-menu.active {
        display: flex;
        animation: nav-menu-slide-down 0.2s cubic-bezier(0.645, 0.045, 0.355, 1);
    }

    @keyframes nav-menu-slide-down {
        from {
            opacity: 0;
            transform: translateY(-8px);
        }
        to {
            opacity: 1;
            transform: translateY(0);
        }
    }

    .nav-menu li {
        border-bottom: none;
    }

    .nav-menu li:last-child {
        border-bottom: none;
    }

    .nav-menu a {
        display: flex;
        align-items: center;
        padding: 8px 12px;
        color: rgba(255, 255, 255, 0.85);
        border-radius: 6px;
        font-size: 14px;
        font-weight: 400;
        transition: all var(--transition);
    }

    .nav-menu a:hover {
        background: rgba(255, 255, 255, 0.08);
        color: var(--accent-color);
        opacity: 1;
    }

    .nav-menu a:active {
        background: rgba(255, 255, 255, 0.12);
    }

    .hero h1 {
        font-size: 1.5rem;
    }

    .card-section {
        grid-template-columns: 1fr;
    }
}

/* Narrow mobile optimization */
@media (max-width: 430px) {
    .nav {
        padding: 0.6rem 0.5rem;
    }

    .nav-icon-btn {
        width: 32px;
        height: 32px;
        min-width: 32px;
        min-height: 32px;
        border-radius: 4px;
        font-size: 1rem;
    }

    .nav-toggle {
        width: 36px;
        height: 36px;
        min-width: 36px;
        min-height: 36px;
        border-radius: 4px;
    }

    .nav-toggle span {
        width: 18px;
        height: 2px;
        margin: 2px 0;
    }

    .nav-toggle.active span:nth-child(1) {
        transform: rotate(45deg) translate(4px, 4px);
    }

    .nav-toggle.active span:nth-child(3) {
        transform: rotate(-45deg) translate(4px, -4px);
    }

    .main-content {
        padding: 0.4rem;
    }

    .footer {
        display: none;
    }
}

/* Base button styles */
button, .btn {
    padding: 0.75rem 1.5rem;
    font-size: 1rem;
    border: none;
    border-radius: 4px;
    cursor: pointer;
    font-family: inherit;
    transition: all var(--transition);
}

button:hover, .btn:hover {
    opacity: 0.85;
}

/* Base form elements */
input, textarea, select {
    width: 100%;
    padding: 0.75rem 1rem;
    font-size: 1rem;
    line-height: 1.5;
    border: 1px solid var(--input-border);
    border-radius: 4px;
    background-color: var(--input-bg);
    color: var(--text-primary);
    transition: all var(--transition);
    font-family: inherit;
    box-sizing: border-box;
    vertical-align: middle;
}

input:focus, textarea:focus, select:focus {
    outline: none;
    border-color: var(--accent-color);
    box-shadow: 0 0 0 2px rgba(0, 217, 255, 0.15);
}

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

/* Login Box */
.login-box {
    max-width: 400px;
    margin: 2rem auto;
    background: var(--card-bg);
    padding: 2rem;
    border-radius: 8px;
    border: 1px solid var(--border-color);
}

.login-box h2 {
    text-align: center;
    color: var(--accent-color);
    margin-bottom: 1.5rem;
}

.form-group {
    margin-bottom: 1rem;
}

.form-group label {
    display: block;
    margin-bottom: 0.5rem;
    font-weight: 500;
    color: var(--text-secondary);
}

.btn-primary {
    width: 100%;
    background-color: var(--accent-color);
    color: #0D1117;
    font-weight: 600;
}

.btn-primary:hover {
    opacity: 0.85;
}

/* Alert Messages */
.alert {
    padding: 0.75rem 1rem;
    border-radius: 4px;
    margin-bottom: 1rem;
}

.alert-error {
    background-color: rgba(255, 82, 82, 0.1);
    color: var(--danger-color);
    border: 1px solid rgba(255, 82, 82, 0.3);
}

.alert-success {
    background-color: rgba(0, 200, 83, 0.1);
    color: var(--success-color);
    border: 1px solid rgba(0, 200, 83, 0.3);
}

/* Trading Page Styles */
.page-title {
    color: var(--accent-color);
    margin-bottom: 1.5rem;
    text-align: center;
}

.status-card {
    background: linear-gradient(135deg, var(--bg-secondary), var(--bg-tertiary));
    color: var(--text-primary);
    border: 1px solid var(--border-color);
}

.status-card h3 {
    color: var(--text-primary);
}

.status-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 1rem;
    margin-bottom: 1rem;
}

.status-item {
    text-align: center;
}

.status-item .label {
    display: block;
    font-size: 0.8rem;
    opacity: 0.6;
}

.status-item .value {
    display: block;
    font-size: 1.2rem;
    font-weight: bold;
    font-family: 'JetBrains Mono', monospace;
}

.action-buttons {
    display: flex;
    gap: 0.5rem;
    justify-content: center;
}

.form-row {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 1rem;
}

.checkbox-group {
    display: flex;
    align-items: center;
}

.checkbox-group input {
    width: auto;
    margin-right: 0.5rem;
    margin-bottom: 0;
}

.control-buttons {
    display: flex;
    gap: 1rem;
    justify-content: center;
}

.btn-success {
    background-color: var(--success-color);
    color: #0D1117;
}

.btn-success:hover {
    opacity: 0.85;
}

.btn-danger {
    background-color: var(--danger-color);
    color: #fff;
}

.btn-danger:hover {
    opacity: 0.85;
}

.btn-secondary {
    background-color: var(--bg-tertiary);
    color: var(--text-primary);
    border: 1px solid var(--border-color);
}

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

.table-container {
    overflow-x: auto;
}

table {
    width: 100%;
    border-collapse: collapse;
    font-size: 0.9rem;
}

th, td {
    padding: 0.75rem 0.5rem;
    text-align: left;
    border-bottom: 1px solid var(--border-color);
}

th {
    background-color: var(--table-header-bg);
    font-weight: 600;
    color: var(--text-secondary);
}

tr:hover {
    background-color: var(--table-hover);
}

.text-success {
    color: var(--success-color);
}

.text-danger {
    color: var(--danger-color);
}

.text-warning {
    color: var(--warning-color);
}

.signal-buy {
    color: var(--success-color);
    font-weight: bold;
}

.signal-sell {
    color: var(--danger-color);
    font-weight: bold;
}

.signal-hold {
    color: var(--text-secondary);
}

@media (max-width: 768px) {
    .status-grid {
        grid-template-columns: repeat(2, 1fr);
    }

    .form-row {
        grid-template-columns: 1fr;
    }

    .control-buttons {
        flex-direction: column;
    }

    table {
        font-size: 0.8rem;
    }

    th, td {
        padding: 0.5rem 0.25rem;
    }
}

/* Coin List Styles */
.refresh-bar {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 1rem;
}

.last-update {
    font-size: 0.85rem;
    color: var(--text-secondary);
}

.loading {
    text-align: center;
    padding: 2rem;
    color: var(--text-secondary);
}

.coin-list {
    display: grid;
    gap: 1rem;
}

.coin-card {
    background: var(--card-bg);
    border-radius: 8px;
    border: 1px solid var(--border-color);
    overflow: hidden;
}

.coin-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1rem;
    background: var(--bg-tertiary);
    color: var(--text-primary);
}

.coin-name {
    font-size: 1.2rem;
    font-weight: bold;
}

.coin-rsi {
    padding: 0.25rem 0.5rem;
    border-radius: 4px;
    font-size: 0.85rem;
    font-family: 'JetBrains Mono', monospace;
    background: rgba(255, 255, 255, 0.1);
}

.coin-rsi.rsi-oversold {
    background: rgba(0, 200, 83, 0.2);
    color: var(--success-color);
}

.coin-rsi.rsi-overbought {
    background: rgba(255, 82, 82, 0.2);
    color: var(--danger-color);
}

.coin-body {
    padding: 1rem;
}

.coin-row {
    display: flex;
    justify-content: space-between;
    padding: 0.5rem 0;
    border-bottom: 1px solid var(--border-color);
}

.coin-row:last-child {
    border-bottom: none;
}

.coin-row .label {
    color: var(--text-secondary);
}

.coin-row .value {
    font-weight: 500;
    font-family: 'JetBrains Mono', monospace;
}

.profit-up {
    color: var(--success-color);
}

.profit-down {
    color: var(--danger-color);
}

.error-msg, .empty-msg {
    text-align: center;
    padding: 2rem;
    color: var(--text-secondary);
    background: var(--card-bg);
    border-radius: 8px;
}