/* ===== CSS VARIABLES ===== */
:root {
    --bg: #0a0e17;
    --surface: #111827;
    --text: #e2e8f0;
    --text-secondary: #94a3b8;
    --accent: #3b82f6;
    --accent-light: #60a5fa;
    --accent-glow: rgba(59,130,246,0.3);
    --border: #1e293b;
    --border-light: #334155;
    --error: #ef4444;
    --success: #22c55e;
    --radius: 12px;
    --radius-lg: 16px;
    --font-sans: system-ui, -apple-system, 'Segoe UI', Roboto, sans-serif;
    --transition: 0.2s ease;
}

body.light-mode {
    --bg: #f8fafc;
    --surface: #ffffff;
    --text: #0f172a;
    --text-secondary: #475569;
    --border: #e2e8f0;
    --border-light: #cbd5e1;
}

/* ===== RESET ===== */
*,*::before,*::after{margin:0;padding:0;box-sizing:border-box}
html{scroll-behavior:smooth}
body{font-family:var(--font-sans);background:var(--bg);color:var(--text);line-height:1.6;-webkit-font-smoothing:antialiased;min-height:100vh}

/* ===== HEADER ===== */
.site-header{position:fixed;top:12px;left:50%;transform:translateX(-50%);width:calc(100% - 24px);max-width:1100px;z-index:100;border-radius:var(--radius-lg);background:rgba(10,14,23,0.78);backdrop-filter:blur(16px);-webkit-backdrop-filter:blur(16px);border:1px solid rgba(255,255,255,0.06);box-shadow:0 8px 32px rgba(0,0,0,0.3)}
body.light-mode .site-header{background:rgba(248,250,252,0.85);border-color:rgba(0,0,0,0.06)}
.header-inner{display:flex;justify-content:space-between;align-items:center;padding:0.5rem 1.2rem;gap:1rem}
.logo-link{display:flex;align-items:center;gap:0.5rem;text-decoration:none;color:var(--text);flex-shrink:0}
.logo-img{width:36px;height:36px;border-radius:8px;background:var(--surface)}
.logo-text{font-size:1rem;font-weight:700;color:var(--accent-light);white-space:nowrap}
.nav-actions{display:flex;align-items:center;gap:0.75rem;flex-shrink:0}
.nav-hint{font-size:0.8rem;color:var(--text-secondary)}
.theme-toggle{background:none;border:none;font-size:1.1rem;cursor:pointer;color:var(--text-secondary);padding:0.4rem;border-radius:50%;display:flex}
.theme-toggle:hover{color:var(--accent-light)}

/* Buttons */
.btn{display:inline-flex;align-items:center;gap:0.4rem;padding:0.5rem 1.4rem;border-radius:var(--radius);font-weight:600;font-size:0.85rem;text-decoration:none;cursor:pointer;transition:var(--transition);border:2px solid transparent;white-space:nowrap;font-family:var(--font-sans)}
.btn-primary{background:var(--accent);color:#fff;box-shadow:0 4px 15px var(--accent-glow)}
.btn-primary:hover{background:var(--accent-light);transform:translateY(-1px)}
.btn-outline{border-color:var(--border-light);color:var(--text-secondary)}
.btn-outline:hover{border-color:var(--accent);color:var(--accent);background:rgba(59,130,246,0.05)}
.btn-sm{padding:0.4rem 1rem;font-size:0.78rem}
.btn-lg{padding:0.85rem 2rem;font-size:0.95rem}
.btn-block{width:100%;justify-content:center}

/* ===== SIGNUP MAIN ===== */
.signup-main{padding-top:6rem;min-height:calc(100vh - 6rem);display:flex}
.signup-split{display:flex;width:100%;min-height:calc(100vh - 6rem)}

/* Visual panel */
.signup-visual{display:none;position:relative;overflow:hidden;background:#111827}
.visual-overlay{position:absolute;inset:0;background:linear-gradient(180deg,rgba(10,14,23,0.2) 0%,rgba(10,14,23,0.6) 50%,rgba(10,14,23,0.9) 100%);z-index:1}
.visual-img{width:100%;height:100%;object-fit:cover;filter:blur(2px);transition:filter 0.5s}
.visual-img.loaded{filter:blur(0)}
.visual-quote{position:absolute;bottom:3rem;left:2rem;right:2rem;z-index:2;color:#fff;font-style:italic;font-size:1rem;line-height:1.5;text-shadow:0 2px 10px rgba(0,0,0,0.5)}

/* Form panel */
.signup-form-panel{flex:1;display:flex;align-items:center;justify-content:center;padding:2rem 1.5rem 3rem}
.form-container{width:100%;max-width:440px}
.form-header{margin-bottom:2rem;text-align:center}
.form-header h1{font-size:clamp(1.6rem,4vw,2rem);margin-bottom:0.5rem}
.form-header p{color:var(--text-secondary);font-size:0.9rem}

/* Social buttons */
.social-signup{display:flex;flex-direction:column;gap:0.7rem;margin-bottom:1.5rem}
.btn-social{justify-content:center;padding:0.7rem 1.5rem;font-weight:600;font-size:0.9rem;gap:0.7rem}
.btn-google{width: 100%;background:#fff;color:#1f2937;border-color:#d1d5db}
.btn-google:hover{background:#f9fafb;border-color:#9ca3af}
.btn-facebook{width: 100%;background:#1877f2;color:#fff;border-color:#1877f2}
.btn-facebook:hover{background:#166fe5;border-color:#166fe5}

/* Divider */
.divider{display:flex;align-items:center;gap:1rem;margin:1.5rem 0}
.divider::before,.divider::after{content:'';flex:1;height:1px;background:var(--border)}
.divider span{font-size:0.78rem;color:var(--text-secondary);white-space:nowrap;text-transform:uppercase;letter-spacing:0.05em}

/* Form */
.form-group{margin-bottom:1.2rem}
.form-group label{display:block;font-size:0.85rem;font-weight:600;margin-bottom:0.4rem}
.optional{font-weight:400;color:var(--text-secondary);font-size:0.78rem}
.input-wrapper{position:relative}
.input-icon{position:absolute;left:0.9rem;top:50%;transform:translateY(-50%);color:var(--text-secondary);font-size:0.9rem;pointer-events:none}
.form-input{width:100%;padding:0.75rem 0.9rem 0.75rem 2.6rem;background:var(--surface);border:1.5px solid var(--border);border-radius:var(--radius);color:var(--text);font-size:0.9rem;font-family:var(--font-sans);transition:var(--transition)}
.form-input:focus{outline:none;border-color:var(--accent);box-shadow:0 0 0 3px rgba(59,130,246,0.15)}
.form-input::placeholder{color:var(--text-secondary);opacity:0.6}
.form-error{display:block;font-size:0.75rem;color:var(--error);margin-top:0.3rem}
.toggle-password{position:absolute;right:0.7rem;top:50%;transform:translateY(-50%);background:none;border:none;color:var(--text-secondary);cursor:pointer;padding:0.3rem}

/* Checkbox */
.checkbox-group{margin:1.5rem 0}
.checkbox-label{display:flex;align-items:flex-start;gap:0.6rem;font-size:0.82rem;color:var(--text-secondary);cursor:pointer;line-height:1.4}
.checkbox-label input[type="checkbox"]{width:18px;height:18px;margin-top:2px;accent-color:var(--accent);flex-shrink:0}
.checkbox-label a{color:var(--accent-light);text-decoration:underline}

.form-footer{text-align:center;margin-top:1.5rem;font-size:0.85rem;color:var(--text-secondary)}
.form-footer a{color:var(--accent-light);text-decoration:none;font-weight:600}

/* ===== RESPONSIVE ===== */
@media(max-width:639px){
    .nav-hint{display:none}
    .logo-text{display:none}
    .signup-form-panel{padding:1.5rem 1rem 2rem}
}
@media(min-width:768px){
    .signup-visual{display:block;flex:0 0 45%;max-width:45%}
    .signup-form-panel{flex:1;padding:3rem 3rem 4rem}
}
@media(min-width:1024px){
    .signup-visual{flex:0 0 50%;max-width:50%}
}

.mini-spinner {
    display: none;
    width: 16px;
    height: 16px;
    border: 2px solid rgba(255,255,255,0.2);
    border-top-color: #fff;
    border-radius: 50%;
    animation: spin 0.6s linear infinite;
}
@keyframes spin { to { transform: rotate(360deg); } }
.btn-primary:disabled {
    opacity: 0.35;
    cursor: not-allowed;
    transform: none;
}